didnt know

so the day after my birthday(June 10) I lost my virginity and he came in me. he bought plan b and I took 3 test (clearblue) 15 days later. I got my period like I was supposed to but it was super heavy. I have been on my period for 13 days now, my normal period cycle is 7 days. I was hurting really bad this morning he takes me to the hospital (he was just a random person I met off of whisper and we haven't had sex since he took my virginity) turns out I had miscarried.

I thought you werent suposed to get periods while pregnant.