I have been on birth control (the pill) for about 4 years, and have taken it religiously. Always at the same time and never miss a pill. I am about 2 weeks out from when I get my period, and I am experiencing bleeding. The blood is very pink, almost like it's coming from a cut. I had sex four days ago, without a condom but with pulling out, and the bleeding started the day after. I also have a sore abdomen and my breasts are tender. I have been having sex using this exact method for the past 4 years and have never experienced bleeding in between my periods. Just wondering what the possibilities could be?