Should I be worried?

So the pill is something like 91% effective for standard use, and my boyfriend and I are very sexually active, rarely with condoms. I’m on the pill, but I think I may have gotten pregnant. We’ve had sex every weekend for the past several months, as well as on wednesday two weeks ago, the day after my period ended. I’ve been really emotional the past couple weeks, and I started getting migraines this week. Today (2 weeks out from my period either direction) i started bleeding heavily after a few days of period type cramps. Could that have been a miscarriage? I didn’t take plan b or anything because i didn’t realize how possible getting pregnant was!