Bleeding

I've been on birth control since Sept 2013. I stopped them for a month in march and started them again in april. I was put on it initially cos I suffer from endometriosis and then the doctor asked me to continue for the added purpose of contraception. This month, I missed one pill in the second week. Now I've started bleeding and I still have 5 more pills from the 21 day pill pack. Is this normal? Any suggestions?