What Causes Irregular Periods Along With Bloating Of Abdomen Post Tubal Ligation?

I have always gotten my period on time...every 28 days to almost the hour. In October I suddenly got it twice in 1month. Then very lite one in November. Then nothing for December and January. Now February and I have been bleeding very heavily for over 9 days with no signs of slowing down. I had my hormone levels checked and all my bloods drawn with everything being normal. I am a 42yo woman with a history of a dvt. I had been taking warfarin for 4 years and switched to xarelto approximately 2.5 months ago. I had a baby 2years ago and had a csection and tubal ligation done. No really bad cramping but completely bloated and some weight gain. What could be going on?