Plus one. Jily is pregnant...at hogwarts.

St. Mungos

Lily, James and the rest of the marauders casually walked down the streets of Hogsmede, laughing all the way. Although they might have seemed, carefree, the truth was- They were scared shitless.
Lily pulled James aside from the rests of the gang, who continued to walk through the snowy streets.
"James?"
"Yeah."
"Are you okay?"
"I think you look fine."
"James- snap out of it. I'm terrified."
"Me too."
"Really? You- scared. Terrified even! It's too good. But god, am I scared. I've never been this scared in my entire life! Not even for the charms final! Or the NEWTs! Are you sure we can do this?"
"We can do this together."
"You're right. Of course you're right."
"Of course he's right!" Padfoot shouted from ahead. "Now get a move on, our you'll be late."
James turned crimson at his now public admittal of fear. "Curse his canine hearing." He muttered under his breath. The gang continued down the sreet. Soon, they approached Madam Puddifoot's Tea Room, and slipped into the alleyway beside the building.
"Okay, here we are. We'll cause a distraction and you two can apparate. Ready?"
Lily turned to James, took his hand and whispered in a voice that only he could hear, "Ready?"
He reciprocated, "No...let's do this."
"Go!" Said Remus. Peter realizing his cue, turned crimson and began to take a step back, looking imploringly at Remus. Remus rolled his eyes and shoved Peter out of the alleyway. Peter immidiately panicked and in the most deadpan and monotone voice possible shouted, "Oh, good god, I've fallen down." At which time he proceeded to lower himself onto the snow clad cobblestones.
"You have got to be kidding me." said Remus as Sirius began laughing hysterically.
"One." Whispered James.
"Two." Whispered Lily.
"Three." Thy whispered in unison.
-oOo-
James and Lily landed smack in the middle of the St. Mungo's waiting room. James attempted to move forward, but found his hand stuck within Lily's. "Lily," he said as he began to move forward once again. "Lily." He said.
"What? Sorry...what?" She asked snapping out of her paralysis.
"I have to go check in, now." He said, a small giggle escaping his mouth.
"Right, of course. Go ahead." But she still held his hand.
"I'm coming back, I'm only going ten feet. Go have a seat." He said. "I love you, I'll always come back."
"Ok." She kissed him on the cheek and went to sit down.
Get ahold of yourself, Lily. Lily sat down and stared at her husband- Did I actually just say that? Her boyfriend.
-oOo-
Gt ahold of yourself, James. James approached the front of the line and cleared his throat to gain the attention of the witch behind the counter.
"Yes?" The mousy witch said.
"Hi, my name is James Potter. I'm here to check in my wife-" What? "I'm sorry, my girlfriend for a prenatal appointment with Healer Callistus."
He finished.
The mousy witch gave him a look of disapproval, and said, "This way please."
James gestured to Lily to join him, as the witch led them to a room down the hall. She opened the door, ushered them inside and spoke once more, "Healer Callistus will be with you momentarily." With that, she left the room closing the door behind her.

Lily walked over to the examination chair and sat down. No more than three seconds later, Healer Callistus entered the room.
"Hello Ms...Evans." He said as he looked down at his clipboard. "I just wanted to say, that it is perfectly normal, and expected for you to be nervous. Just try to relax, you're in good hands. First, we'll be doing a small, mostly external exam. If you would," he said as he handed lily a paper robe and pulled the privacy screen in front of her. "Please put this on, so we may begin."
She slipped out of her clothes and into the robe. She slowly approached the table and sat back down. Healer Callistus pulled the screen away as Lily was about to put her feet into the stirrups.
"James!" She said, tilting her head towards the wall and beckoning him to come towards her head.
"Okay," Said Healer Callistus. "As I suspected, you are about 6 weeks along in your pregnancy." He waved his wand over her abdomen and continued, "The baby was conceived on the night of January first, you will begin to show in April or May, and you will be having-" He looked at Lily and James. "Do you want to know the sex?"
James looked confused. "You just told us- January first." Lily rolled her eyes.
"The sex of the baby, James. And I think so." Lily uttered through slightly gritted teeth.
"Oh! What is it!" He asked nervously.
Healer Callistus began again, "You're going to be having a boy. Congratulations. Everything you will need is in," He reached under the table and conjured a blue backpack. "This backpack. Prenatal potions, some potions to ease symptoms and the like."

He waved his wand over Lily's abdomen once more and an image of the baby appeared in the air. It looked no bigger than a bean, in fact, neither Lily not James could see it. He uttered an additional spell and a faint heart beat became audible. James, who had sat down, and Lily who had closed her eyes, both looked up immediately. James strode over to Lily and gazed deeply into her eyes. He grabbed her hand.
Healer Callistus waited for Lily or James to speak, but they were both too awestruck to make a sound. "If you don't have any questions, I have many patients to attend to. I think you'll be just fine." He left the room with a smile and closed the door. Lily sat up and looked at James.
"I-I can't believe that was our baby."
He said.
"It's amazing...I just want you to know, that I know this isn't ideal...but I couldn't be happier that this is happening with you." Lily said. She magicked on her clothes and stood up once more.
"Let's go back." James said. He grabbed Lily's hand, and if the backpack over his shoulder. With that, they apparated back to Hogsmeade.
-oOo-
"...and basically, we're running out of the dorms casting off hexes and curses at random. Barely made it out for our lives." Finished Sirius.
"So that means, that he was so hammered from fire whiskey, he stumbled out of his bed, used the Lumos charm and than went back to sleep." Said Remus.
Sirius was seething. The girls he was chatting up were walking away, as Remus rolled his eyes and nudged Wormtail in an attempt to snap him out of his complete awe.
"Do you always use that story?" Asked Lily, emerging from the alley.
"Yes." Answered the other four in perfect unison.
"So how'd it go?" Asked Remus.
"Yeah, how're your bits, Evans?" Sirius asked. Remus held James back to prevent further turmoil.
"It was fine...quite amazing, actually. We heard his heartbeat. I can't believe he's inside of you. " James was completely dazed, and utterly confused. The lads thought it amusing, but Lily found it beautiful.