A condom broke on my boyfriend and I when we had sex a few days after my period ended. I took plan B within the same hour and he didn't finish inside of me. I experienced no symptoms but about a week later I got what looks like my period, but isn't its not as heavy and its brown. I've since been having this for a week. What is this? Should I be concerned I'm pregnant? I have sore breasts which usually happens about two weeks before I get my period (its supposed to come in about 2 weeks). I'm just concerned because this 'bleeding' has been happening for quite some time now and have never experienced this side effect of taking plan B before.