A/N Okay, I wrote this using the alpha/beta/omega dynamics... which I know naff all about if I'm honest, so it's more my version of the dynamics. This is my first foray into these dynamics, teenlock and mpreg, all at once, (feeling brave here!), so please be nice!

Oh, and the Holmes boys get along in this one... I know, mad right? ;)

Sherlock Holmes was seventeen years old. He was also an omega, much to his parents' horror. And when he said 'horror', he meant 'horror'. They'd schooled it into him since the day he'd presented at fifteen: don't have sex. No exceptions.

His brother, older and wiser than him at twenty-four - not to mention out from under Mummy's beady eye - had been providing him with contraceptives in secret ever since. 'Just in case', Mycroft had said the first time. Sherlock had known his brother would understand. Mycroft was a beta but he knew enough about omega physiology to know that Sherlock would relieve the discomfort of his heat at some point. 'You should have a choice to be safe about it', he'd said when they'd talked about it in more depth - the first time Sherlock had stayed with him at his London flat.

Mycroft was the one person he trusted enough to go to for advice. So when he found himself with a problem of a kind that only an omega could have, Sherlock did what was, to his mind at least, the only thing he could do. He got on a train to London and got a cab from King's Cross to his brother's office. He let himself in with a pass card Mycroft had given him 'for emergencies' and hurried past the deserted reception desk. He stabbed impatiently at the lift button for the fourth floor.

Mycroft's office was the fourth door on the left; standing outside, Sherlock took a deep breath - and then two more for good measure - then knocked.

"Come." Instructed his brother's, slightly peeved, voice. Sherlock entered, swallowing nervously. Of course, he thought as he entered and discovered why his brother had sounded peeved, of course he was in a meeting. He needn't have worried though, the moment Mycroft saw that it was him, all annoyance receded from his features to be replaced in turn by surprise, then delight, followed promptly by a hint of worry.

"Sherlock!" He exclaimed "What on earth are you doing here?"

"I need to speak with you. Urgently." He cast a glance at his brother's companions "And privately." He added.

"Of course." Mycroft said, looking a shade more worried as he nodded towards a door that, Sherlock knew, lead into a small seating area that doubled as Mycroft's bedroom when he was extremely busy. That was more often than not these days. "I shall join you presently." Sherlock nodded smartly once and headed into the next room, where he sat and fretted for nearly fifteen minutes before his brother at last entered.

"Brother-mine, what on earth is wrong?" He exclaimed, immediately upon closing the door behind him.

Sherlock opened his mouth and froze. Where the hell did he start?

"I find the beginning is always an excellent place to begin a tale." Mycroft said, softly, as though he'd read his brother's mind.

Sherlock watched as Mycroft settled himself in the armchair opposite him and then, slowly, he began - as suggested - at the beginning. "I've been using… those things you get me." He began, awkwardly

"You are at perfect liberty to do so, Sherlock." Mycroft replied, smiling slightly. "I am, however, glad to hear you're being responsible about safety." Sherlock blanched. Mycroft hadn't noticed. Well, if his brother hadn't noticed, at least he could hope to fool Mummy and Daddy for a while longer, he thought, desperately trying to stay positive. "Who is he?"

Sherlock licked his lips. "His name is Greg."

"Not Greg as in the Greg you've had a crush on since primary school?" Mycroft asked, grinning

"That's him." Sherlock confirmed, quickly. "There was a party."

"Oh?" A slight frown creased his brother's brow at this.

"We… went together. I swear I'd taken my pill, I wasn't in heat or anything. "

"Then I see no problem." Mycroft replied, shrugging patiently.

Sherlock licked his lips again. "I haven't had a heat since." He confessed, finally.

Mycroft's face was smooth, his voice perfectly calm as he replied: "You're pregnant."

Sherlock refused to meet his gaze, preferring instead to gaze at the plush red carpet as he nodded the affirmative.

"Sherlock. Look at me please."

Sherlock complied, reluctantly.

"It will all be okay. I promise you that much." Mycroft said, earnestly, leaning forward in his chair to take both of his brother's hands in his own reassuringly.

"Mummy and Daddy-" Sherlock began

"Will have their own opinion," Mycroft cut in smoothly "to which they are entitled. What it is, however, is not relevant."

Sherlock looked up in surprise "It isn't?"

"Not in the slightest." Mycroft assured him, gently. "Now, have you told him? Greg I mean."

Sherlock shook his head. "It was a once off, we were drunk and everyone was doing it. He won't want to know."

"Sherlock! What have I told you? Drinking alcohol negates the pill!"

"You never-" Sherlock paused "Okay, I may have deleted it." He said, thoughtfully.

"Well for goodness sake recover it this instant! Dear lord!" Mycroft replied, pinching the bridge of his nose between forefinger and thumb for a moment "Now, I advise you to tell him, soon, before he finds out by some other means."

"I-"

"Sherlock, wouldn't you want to know? If you were in his shoes?"

"I suppose." Sherlock allowed, grudgingly

"Then you must tell him. If he wants nothing to do with it, then that is his decision, but it is not one that you can make for him. He must be given the choice."

"You're assuming that I'm keeping it."

Mycroft looked at him sharply "Aren't you?"

"I don't know." Sherlock admitted, quietly "It's what Mummy will want."

"And I have told you it makes no difference! You must make your decision, whatever it may be, because this is your body and your baby. Leave Mummy and Daddy to me."

"But they'll-"

"Leave them to me." Mycroft repeated, firmly. "Now, how far overdue are you?"

"Three weeks, but it's five since the party."

"Then we still have some time until the decision is no longer yours. I suggest that you make up your mind as soon as possible. At that point we can make any necessary arrangements."

"I can't raise it alone Myc."

"You don't yet know that you'll have to."

"We can pretty safely assume. Could you arrange it?"

"Arrange it?"

"You know…"

"An abortion?"

"Mmm." Sherlock replied, fiddling with a stray thread on the sleeve of his tan jacket.

"I could," Mycroft said, reluctantly, "if necessary."

"Will you, please?"

"Sherlock, if you cannot say the word, how can you expect to fare undergoing such a procedure?"

"Abortion." Sherlock replied coldly, his voice emotionless.

Mycroft surveyed him for a moment, almost sadly. "Very well, if you wish, I shall arrange it."

"Good."

"You still must tell him Sherlock."

"Let me worry about that." Sherlock insisted.