Hi, I Took Plan B Last Week After My Boyfriend

Hi,

I took plan b last week after my boyfriend and I had sex. I was on my period but right before we had sex there was no blood. Thinking I was off. The condom broke and within 20 mins I took plan b. But I've had cramps and I just what seems to be my period but also brown discharge seems to be coming out. I'm afraid I might be pregnant.