I took plan B before my period and I did get my period not just spotting, it ended on the 26th of Dec, had protected sex on the 16th of January. Condom broke when he was inside but he never came. After that we stopped. My period came 4 days late but it was heavy for 2 days and ir died off on the third. Could it be implantation or is it just plan B messing my second period? Thank you