Could I be pregnant

I take my pills by way of skipping the "sugar" pills in order to not have a period due to a history of endometriosis. I missed four pills this past moth, but I took each pill the following morning and took the regular day's pill that night, so even though a day was missed the pills were taken. Now I have been taking my pills without a missed one for 12 days and have been bleeding for nine days straight and have sever cramps on and off and especially right after I take my pill. My period when I used to have one never lasted more than three to five days max and if five days only two days were heavy. This bleeding I have now is heavy on and off and bright red on and off. My BF is worried hat it's may be a miscarriage. I don't know what to think.