20 days late!??

Naisha

Ok help lol I’m not sure what is going on with my body. I have been late 20 days now last start day was Jan 7 lasted to the 12th. I had been feeling all the symptoms like I was on my period this month, but no blood. My sex drive has been high. I’ve taken 4 pregnancy test, all negative. I did change my diet on first day of the new year, I’m vegan. But I have been vegan for long periods of time before, I still always got my period even though it was short and light. Also I had sex the other night and then there was a lot of blood, but it wasn’t really red it was light like watered down blood, but I still thought great I started finally, but no the next day it was gone. And nothing still any info would be greatly appreciated!