Period help!

Ok so I'm on birth control but I have a few questions maybe somebody can answer them.. I've been on birth control for a little over 3 years and everything's been going good except I got my period on the day you take the last pills that allow you to get your period and so far it's lasted 4 days. Usually I only get it for 2 days only a little but also something else weird was happening. I got it a lot and I mean extra!! The first 2 days were good then in the 3rd day it went away which made me happy but then later that day it came back!! And it was only a little then all of a sudden a lot again!! The next day came which made it day 4 and it was gone then again I was relieved but later on it happened again 😒 what is up with me?!? It's now going on day 5 and in the morning it was a little then so far nothing else I'm hoping when I wake up it will be gone!! 😫