AF is being weird!

So my AF normally lasts 4-5 days with bad cramps the first 2 days. Last month (August) my AF was only 2 days & completely stopped, then came back very light 1 day later & stopped that night. This month when it came it only lasted 1 1/2 days & stopped completely & came back a day later even lighter (didn't have to wear anything for protection) & went away again... Nothing in my life has changed as far as diet, exercise, eating habits... Is this normal for anyone else? I want to take a test but I'm scared for a negative again.