I have been on Birth Control for almost 2 years straight now, and this current pill for 7 months, I have never experienced breakthrough bleeding before. I didn't miss any pills this cycle, although I did start my pill pack a day late, but I caught up that day. I have done this before and never had a problem like this. I started spotting very very light pink and brownish it lasted on and off for three days. I am not due to start my period for another week. Also, my husband and I do have unprotected sex. Could this be implantation bleeding, and could I be pregnant???