What Causes Prolonged Menstruation?

I am 19 years old. I was 2 weeks late on my period. I finally got it and I have now had it for 2 weeks. It started out with light spotting and after the first week is got a little bit heavier, but not as heavy as my period usually is. I have had no cramps at all and that is very strange because I am usually in so much pain. I got off my birth control Pills a couple months ago, so I don't know if that has anything to do with it. Is something wrong?