Im only 17 so please don't judge.

Me and my boyfriend have been sexually actively for around 2 months now and I'm on the pill and we used a comdom because I had forgot my pill the week before. Anyway fast forward my period didn't come so I took a test and it came back positive, I was so scared but then the following day I started bleeding. Heavily and very bad cramps.

Usually my periods are 3 days long but I'm still bleeding just over 7 days now.

I just want opinions as I'm not sure what's happened?

Thankyou, please don't judge.