Hello, I started my period 2 weeks ago. It always last about 4 to 5 days. I will stop for one day but start again the next day again for two to 3 days. then stop then start. why? I have endometrisis does this have anything to do with that? I am not on birth control and im 23 years old, 5'9 and 110 lbs. I also have only one ovary due to me havinng cyst. Help this has never happened to me and my sugary for my ovary was a year ago.