My symptoms are very similar to yours. I have just gone 7 weeks between periods and I have now been bleeding for about 5 weeks, with no signs of it stopping. I see my GP a week ago and have been referred for a scan, but am going back to see a different GP (mine is on holiday) on Monday as I am worried about my iron levels.
Can I ask were your iron levels affected? and do your periods stop on their own or did the GP give you something to stop them?