Periods are dumb!! Late period issue

I am so annoyed, my period is being so dumb lately! Last cycle I was 7 days late took tests and nothing and it came on but then my period lasted 10 days! Went and got blood work to see if it was a hormone issue which it wasn't and now this cycle I am 13 days late. Wtf body, get your shit together! I haven't tested yet because I think my body is just being a jerk again. Anyone else have this problem? Not trying to conceive but wouldn't be mad if it happened, so I'm not stressing about getting a positive test just annoyed at the uncertainty.