Please help

Alexandra

I been on birth control for over a year on the pill. I started period on January 10 and lasted couple of days. I been taking my pill everyday sometimes I'll miss a day or two but I will take double the next day. I am sexually active with my husband we dont use another protection beside my BC. I been feeling sick like cold like symptoms and today the 27 I just started bleeding. I never had this happen to me. What can it be?