Well to start my girlfriend and i have been sexually active for 4 months which the whole time she has been on the pill. for the past 2 months we have decided to do it without a condom and last week she was convinced she was pregnant. she took 4 tests 2 came out positive and 2 came out negative and she gained a little bit of weight 10-13 pounds. but yesterday she felt like c**p and unexpectedly started her period (she thinks) but her sugar pill isn't for 2 weeks. she said it was a different kind of bleeding almost like menopausal just a little different texture and color. she does have cramps and some pains but im not sure if the pill would cause a miscarriage if it failed to work and why she would start her period two weeks earlier?