I have been on birth control pill for about 5 years now. I have taken it at the same time everyday this month. Last month was a little irregular but never missed a pill by more than 10 hours. I have had sex this month with no condom.  I checked the mucus around my cervix today and it was a light pink. I am supposed to start my period in 2 days. Is the pink color just a sign my period is coming?