So late, not pregnant?

I’m almost always on time and start within 2 days of the date I’m supposed to, but I’m 13 days late and definitely not pregnant? Aside from not having any sort of sex, I’ve also taken a 2 tests just to ease the irrational fears that sometimes come with being late. I’m not sure if I should see a doctor? I haven’t had any of the symptoms I usually get so it doesn’t feel like anything is wrong, but this is super out of the ordinary. Advice?