I took plan b and got my period at the expected time two weeks after. (The condom slipped off and we wanted to be safe). We had sex four days after the start of my period, the condom broke during sex, neither of us realized until the end (I told him to pull out just in case, thank god, but some still got inside). I took plan b eight hours after the incident. Six days later (today) I woke up to light brown discharge and light cramps. There is new blood. Could this be implantation bleeding? Am I pregnant? I plan on starting birth control a few weeks from now.