My Period is SOOOOO LATE! But I’m not pregnant

Goodmorning everyone 💜 I hope all is well when you see this post. I have questions and I honestly don’t know where to start looking. I’m a 20 year old that like 115 lbs and 5”5. I’ve always been small with a very high metabolism. I stopped taking my birth control in Oct of 2020 so a year and some change ago. My boy friend and I are currently renovating a bus so it can be our full time home. That project is stressing me out, ontop of other stress. My period is late by 106 days.

No pms

No ovulation pains

No positive pregnancy tests

But the outside of my uterus is tender to the touch. So much so that if my bf places his had on my uterus it gets uncomfortable. What do I do? I don’t want to self diagnose but I’m honestly scared. Please help 💜💜😅