Started taking birth control on Friday and my period was due that day too, also took plan b as I had sex on the 29Nov (Saturday) and the doctor prescribed me them. But my birth control doesn't start to work until 9 days later. We used protection plus he didn't cum inside or anywhere near my vagina. I've taken pregnancy tests from the start of November to now all came out negative. Will plan B fuck up my cycle or do you think I'm pregnant. In concerned