So…. I have fallen in love with Med too! And of course the other Halstead brother ;) I mean really how could you not… lol anyways, I stumbled across Med fan fic the other day and was absolutely ecstatic… and then I watched Med tonight and seriously…. It was the best! Anyways this idea came to me and I decided to run with it. And I know the timeline with Will coming back doesn't really match but this is slightly AU since we haven't seen it yet so I'm just running with it. Hope you enjoy :)

Will and Natalie had been together about two months. She'd been his best friend through med school and until he'd gone overseas. Then when he came back she was married and he went to New York. When he finally returned to Chicago, he wasn't in the best of places and Jeff had just deployed.

It took about three months and a lot of growing up for him to get his best friend back. Just as they were getting to that good place in and out of work, Jeff was killed and Nat found out she was pregnant. Will stayed with her through it all.

He'd grown up a lot in the six months he'd been back in town, thanks in part to Nat, but work and Jay helped too. Jay stayed on him the whole first month to get it together and grow up. He'd let his brother down so much, especially with their mom, that he wasn't letting him down again. So he stayed with Jay for three months and then got his own place.

By then, Nat was depending on him and he was staying with her most nights, just holding her while she cried for her husband and her baby that would never know him. In the next three months he proved to her that he was still the guy she remembered, the guy that stole her heart in med school, and that she still loved. He was always there for her, even when she didn't ask for it, he never let her down.

When she was seven months pregnant, Will worked up the nerve to ask her out on a date; mainly thanks to Jay and Erin pushing him too. He was surprised and so glad when she agreed. After that, they were inseparable. They put the baby's room together, worked pretty much the same shifts, and by her eighth month they were more or less living together. They hadn't officially moved in together, but he stayed over most nights.

Every day he felt himself falling more in love with her. Even though the baby wasn't his biologically, he felt like she was his, loved her like she was his. Nat had decided not to find out what the baby was, and he was ok with that, but he knew it was a girl. She still had rough days where she would feel guilty about moving on and Jeff not being there, but those days were getting fewer the more time she spent with him.

She'd been home on maternity leave for the last week, and Will was anxiously waiting for the arrival of the baby. Just thinking about her and the baby made him smile. He knew he loved them both, even if they hadn't said it yet, and he couldn't wait to meet the little bundle of joy that was going to change their lives.

He had about an hour left on shift and he checked his phone for an update. Nat had been texting him off and on all day telling him how far apart her contractions were and that she was still ok. He was just about to call and check on her when Jay called.

"Hey little brother. What's up?" Will asked, knowing it was rare for Jay to call while he was on shift.

"Don't panic, Nat called us and wanted us to bring her in. She's ok, her contractions are just closer together. We'll be there in 10."

Despite his excitement, things were fixing to get real, and real quick. "Maggie, Jay and Erin are bringing in Nat. Get me a room ready and take me off the clock," he called heading out the doors to wait on them. He was trying hard not to panic, but truth be told he was terrified to become a dad. He'd never had the best example, but he was damn sure going to do better.

He waited out front even though it was freezing cold thanks to Chicago's lovely winter. He was instantly by her side when Jay pulled up. "Hey baby," he whispered when she grabbed his hand. "You ready?" he smiled rubbing her back. She doubled over as another contraction hit her before she could respond.

He felt so helpless seeing her in this much pain. He scooped her up and carried her inside as she was catching her breath. "It hurts… god Will… it hurts," she cried as he laid her down on the bed in the room Maggie pointed him into.

"It's ok Nat. We'll get you something ok?"

"We'll be in the waiting room… Good luck," Jay smiled patting his back as him and Erin went out the door. Will helped her change into the gown and laid down with her rubbing her back. He knew it'd been bothering her even before she went into labor, and he was trying anything to make this easier on her.

Just as he was going to find her doctor, Maggie and April walked in. "Hey, Mama," April said and Nat just groaned. Maggie and April couldn't contain their laughter at the terrified look on Will's face. "It's normal," Maggie said and he just glared at her. Maggie and April shared a look; he had it bad for Nat and the baby.

Natalie looked up at him with tear-filled eyes after Maggie and April hooked her all up. "It's ok Nat. I'm not leaving." He rubbed her back a little harder, wishing he could take the pain away. She squeezed his arm until her knuckles turned white. "Breathe, Nat, just like they showed us." He breathed like they'd show them in that birthing class she'd wanted to go to trying to get her to match his breathing. "That's it, Nat," he smiled.

She gasped. "Will… need to push!"

He pushed the call button over and over as he rolled her on her back laying behind her. "Can't wait…" she panted sending Will a pleading look.

"Shit…" he mumbled, laying her back on the bed. April came running in; "Where's her doctor?" Will asked.

"Another delivery. What's wrong?" April asked seeing the panicked look on Will's face.

"Push!" Nat panted.

April looked at Will; "You can do this Will. We don't have a choice," she said trying to get him into doctor mode. She yelled for Maggie as she helped Will slip on his gloves and tie the gown over his scrubs. When he turned back, Natalie was already pushing.

"Ok Nat, just you and me. We can do this," he said looking up at her. This wasn't the first baby he'd had to deliver, but it was the most important one. "Ok, Nat, I can see the head. Just a few more pushes ok?"

Two more pushes and the head was out. "Breathe, baby, just hang on and breathe for me," he said cleaning out the baby's nose and mouth. "Ok Nat, one more push. Come on baby," his face had lit up seeing the baby's face. With one more strong push, the baby slid into his hands with a loud cry.

"We did it. She's here Nat. She's here," he said as few tears slipped down his cheeks. He laid the baby girl on Nat's stomach as he cut the cord. April wrapped her up cleaning her off as Natalie cried tears of joy. "A girl," she whispered as Will leaned over and kissed her.

Just then her doctor walked in and Will was so relieved. He stripped his gown and gloves and kissed on Nat's face as they heard the baby crying. Once April measured and weighed her, she bundled her up and carried the screaming girl to Nat.

As soon as she was in her mother's arms, she settled and opened her beautiful brown eyes that were so much like her mother's. Will fell instantly in love with her. "She's so beautiful Nat, just like you," he whispered running his finger along her cheek.

He didn't know it was possible to fill this much love, but these two, these two had filled him with so much love and happiness. After her doctor, Maggie and April stepped out, he laid down in bed with her wrapping his arms around them both. "I love you both so much," he whispered not even thinking about it. It just came natural.

Nat looked at him and smiled so big as a few more tears slipped down her cheeks. "I love you too. I always have Will Halstead, always." She loved watching the smile spread across his face as he leaned down to kiss her.

She was clearly exhausted from having been in labor all day. "Want to hold her?" she asked and he nodded. He carefully cradled the baby girl to his chest. "This… This is amazing," he whispered as the baby looked up at him. Natalie was almost asleep; "Go show her off," she smiled knowing all their friends would want to see her.

"You sure Nat? I mean she's…"

"She's ours," Natalie smiled interrupting him. "I know she's not biologically yours, but you're going to be the one to raise her and love her and be her dad. She's yours too and everyone should know it."

Will leaned down and kissed her hard. "I love you Nat, so so much. Thank you for this, for loving me and giving me this," he smiled.

"I love you too. Now go, so I can rest," she smiled as he got up, still cradling the baby girl to him.

He carried the sleeping little girl out to the waiting room smiling down at her the whole time. "Well?" Jay asked seeing him.

"Everything's ok. Mom and baby are just fine." He smiled down at her. He looked back up at his brother and future sister-in- law turning the baby where they could see her. "Meet your niece, Gracie Ann Halstead. 7 pounds 6 ounces, 19 inches long." He handed Gracie to Erin and watched as they oooed and awed over. She started to fuss a little and Erin handed her back. She quit as soon as she settled back against his chest.

Will couldn't stop the smile from getting bigger. She already knew and trusted him and he loved her all the more. "Your name?" Jay asked with a smile watching Will with her.

He nodded. "Nat and I talked about it and this is what she wants. I don't want anyone but her, never going to leave them, so it seemed right. We'll tell her about Jeff when the time's right, but this, with Nat, is all I want."

"Proud of you," Jay said giving him a side hug because of Gracie. After showing her around the nurse's station, he carried her back to Nat's room.

Will couldn't think of a more perfect day. He had a relationship with his brother again, he had his best friend and the love of his life, and now he had a beautiful baby girl. He sat on the couch watching Natalie sleep.

He still held Gracie close and she was sleeping too. "I may not have helped make you, but you will always be my little girl. I will always love you and take care of you as if you were biologically mine. I already love you more than I could ever imagine, you and your mommy both. You'll always be my girls." He smiled as he laid down on the couch holding Gracie against his chest. It wasn't long and he drifted to sleep too with a smile on his face.

Well I hope you enjoyed this little one shot. I seriously cannot wait to see Will with Nat's baby. And I know Natalie won't give the baby Will's name, but it's such a nice thought.. ;) Anyways hope you'll let me know what you thought :)