Bleeding. Help?...

Hello. Yesterday I started bleeding quite a bit. I am taking the birth control pill though. I have realized at some point I did miss a dosage, and I have been late a few times but I took the dosage and am trying to stay on time of taking it. My husband and I are sexually active quite a bit. I have never had this bleeding issue while taking birth control. Especially when my period isn’t supposed to happen for at least another week... anyone have any ideas what could be wrong?