TMI but HELP

I missed three pills of my BC but continued to take the pills and started bleeding. I had sex with my fiancée but had taken my pill before we messed around. I’ve been bleeding for 13 days when will this end? It fluctuates between heavy and light or it goes away for a day and comes back the next. I have been on BC for four moths now, is this normal? Like stated I had missed a few days but just skipped those days and continued on with the remainder of my pack. Help if anyone knows anything.