what could be wrong??????!!!!!!!!

im on the type of birth control where i take the 21 pills for 3 weeks and for the last week of my pack they're sugar pills. the ones where no medicine is in them so that i can get my period. but.. after having sex with my boyfriend i went to the bathroom and noticed there was a lot of blood when i wiped. i thought he tore something because everything down there burned and there was a stinging sensation through my body. but it went away after a while. and no it isn't any type of std, were both clean. anyway, im not supposed to get my period for another 3 days or so. andddddd i didn't take my sugar pills last month because i was going on a get away vacation with my boyfriend. so i skipped the sugar pills that month and went right into another pack. an no, im not pregnant either. i take my birth control everyday at the same time. im extremely precautious. but what is my body trying to tell me????? is this my period just being early??????