Off pill now super short periods!

When you came off the pill what were your periods like? Mine have been shorter ranging 21-26. Now 21 freaks me out. Also, these five periods I've had off the pill have lasted kind of 2 days! For ten years on the pill they were 5 days and going through my fair share of tampons. This recent period was only one day of red blood! I get no period pain whatsoever just the 'feeling' on one side as if it's the ovary around the suspected ovulation time. After much googling, I've read 21 days cycle is ok but what does seem concerning is the small amount of bleeding - would this mean that my lining just isn't great?