not sure i would call it a period

I started the 22 of September, I usually have my period for maybe 4 days. Well I didnt think much of it till the next friday came, and I was still bleeding. I thought okay Ill be off that night. I woke up the next morning and was still bleeding. I done this back in July and August. I started my normal period but just contiued to bleed. What could be causing this?