Hi, I Went On Birth Control 8 Years Ago. First

Hi, I went on birth control 8 years ago. First on the pill for two years and after that the injection for 4 years. I decided to stop 2 years ago but still haven't had my periods. I'm now getting a bit worried?
Today when I went to the bathroom I did had a TINY bit of blood on the toilet paper (only) and do have heavy stomach ache today. any help?