Period has not stop

So I’ve never had such a long period before and I started my birth control pills 3 or 4 months ago and my period was normal for 4 days and then I realized I was still spotting so I just waited another few days and it still hasn’t hasn’t stopped! I am worried something is wrong, but I don’t want to think negatively. If any of you know what’s going on or have any ideas please leave me a comment! Thank you