Will they know if i had ?

It doubt if it was your period. It was probably skin beeing broken, which happens when you first have with somebody, or in your case in a different way. Either way, does it matter if your doctor knows you have had ? It shouldn't bother you. They cannot leagally tell your parents or anybody else. If your worrying because your under sixteen then they still can't tell anyone, but if your that worried then stop ual sctivity all together untill you are old enough, because if your lying about not doing it, then your obviously not old enough to deal with the consequences of your actions. Unless your ready to tell people, you aint ready or mature enough to do it!