Skipped period and anxiety

Has anyone ever skipped a period and not been pregnant? I’ve taken 6 negative at home tests and I’m 20 days late past my period. I have a gyno appointment next week to see what’s wrong, but i think it’s because i switched from Prozac to Lexapro potentially? That’s the only change i can think of.

I’m a generally anxious person but never skipped a period even during really devastating things so i don’t think that’s it.

The sex i do have is only about once a month and i use a condom and pull out even with a condom. Could someone ease my anxiety please