For the past year and a half I have been super super regular, a set 29 day schedule that lasts 4-5 days. I have only ever been later than that once and I was only 4 days late. My flow is ALWAYS super heavy and I experience super bad cramps. Even when I first start it is super super heavy. This months I was 10 days late and experiencing nausea, sore breasts and I was tired ALL THE TIME. I had taken a test when I was 2 days late and got a negative so I was going to wait until I was 12 days to try again. 2 days ago after being 10 days late I went to the restroom when I wiped there was light pink residue left on the toilet paper but not enough to even use a panty liner. About 4 hours later it got a little heavier but still way light. Yesterday for about 3 hours it got heavy to the point I used a full tampon. Then it went back to being super light. Today it is still super light as to the point it's going to stop in a few hours. I usually never end until the end of the 4th or 5th day. I am super nauseous today, more than I have been and my breasts are still sore. I have not experienced any cramping except a slight uncomfortable feeling in my lower abdomen today, no pain just a weird feelings in the pit of my stomach. Could I be pregnant or is my cycle just doing something completely off?

Sounds more like your cycle is off.