I don't know if this is normal...

Danielle TK
✨be warned this is long✨
My period is always very heavy. By heavy I mean, it's like a murder scene.... I have to change product every two hours (even when wearing a super plus tampon and a overnight pad, at the same time....) 
I know everyone's period is different, but this seems very abnormal to me. I get massive cramping in my lower back and above my pubic bone for a week. 
The blood itself is very dark and large clots, by large I mean they can be over and inch long...
They also last for over 7 days the longest being 9 days long, from the day I start my flow to when it stops and I don't have to wear anything. 
Should I maybe try to get more info from my doctor, I have visited and they always brush it off.
I'm starting to get worried cause my bf and I are considering children, and I'm scared I might find out my parts are no good....
Any advice?