HELP! I have been on Minastrin 24 FE (birth control) for a little bit more than 6 months,I am sexually active (we do and don't use condoms but he pulls out every time) and the last time I was supposed to get my period it came for only one day while on the placebo pills and it was dark blood (which i read means old blood). This period, i got it on the second day of the placebo pill but it is the same way. I have gained a lot of weight recently. Could my body be changing because of the weight or are these signs of pregnancy?