Autism, panic disorder, and periods

I haven't had intercourse or done any sexual foreplay (anal, vaginal, oral, fingering, handjob, mutual mastubation, etc) in 2 1/2 years.

I'm not on birth control.

I got covid-19 on july 13th and my period for july on the 15th.

I had didn't get better untill August 2-3rd.

My period is 15 days late. I've never ever missed a month or been this late.

And my sister who got covid a week before me and also had her period at the same time got her period for this month. She wasn't late...but I am.

I have a panic disorder and autism and ptsd from being rapped...and I tend to spiral real quick into panic mode.

All my mind can think of is "omg what if I got pregnat from sitting on the toilet in the family bathroom (a man/women's restroom) at walmart"

I talked to my mother. She calmed me down and said I didn't need a test. That I know that's not how pregancy happens. That covid most likely messed with my system and my sister's body is diffrent from mine a vice versa.

So I know it's a dumb question, but to help my panic..you can't get prego from a toilet seat right?