Help it won't go away


So I've been off birth control for a little under two years and at first my period started actually being regular. It came around the same time every month and last between 3-8 days. But I've been on it now for almost 5 weeks and it's been heavy. I'm definitely getting all the symptoms. So one day is cramp, the next is emotions, the next is bloating...etc. any ideas on why it could be different or hasn't stopped? Should I see a doctor? Thanks in advance!