Go for complete gynecological examination. There are chances of organic growth in your uterus. There can some fibroids as well. Either case get biopsy.
If You've Been On Your Period For Two Months Straight, I Suggest You Go See A Doctor.
I have that same problem and it's so annoying!
I last even longer then that I have been on for 2 months and ill go of for 4 months then bleed 2 or 3 months.