Bleeding on bc

I take my birth control fairly regularly usually less than a 30 minute difference in time. But if I miss taking it by more than 35 minutes I have horrible cramps and heavy bleeding for an hour or two after I take it. I’ve been on the pill for over a year and my doctor doesn’t seem to really take it seriously. I’m not sure if my body is still adjusting or if I need to try a different birth control method. Has anyone had something similar happen to them while in the pill?