HELP!!

Nikki

Okay so I haven’t had a period since April (I had unprotected sex 5 times, that last time may 19) Today what I think is my period started but it’s completely different than how it’s always been. My periods are usually really heavy but it’s very watery and very bright red almost a pinkish when I wipe with tissue but a little darker on the pad. I’m 19 years old and fairly healthy, could anybody give me any ideas on what you think it could be ?