hi, im 16. during fourplay with my otherhalf i started to bleed with no pain and only for the time a min(6days in to my period) , but i dint worry me as my partner. can get a little roughh and i had no experiance of this before. now a 18days into my period. two days after sex iv noticed that im bleeding again only for a couple of mins. im not on any controception. but me and my partner use a condom with out fail. does anyone know what this could be.?