Supply teacher that knows something very embarrassing about me.. help!

This is so embarrassing but I really need some support. I am really stressing about about this. I hope this is ok to post for support. I guess this is humorous because if I don’t laugh about it I’ll cry lol

So, long story short. I had a boyfriend when I was in secondary school, we broke up at 16. We were each others firsts if you catch my drift. After a particular evening, my ex put a used condom in his bag to dispose of it outside of his house. (As his mother didn’t know.. I didn’t know he had done this). Long story short, his mother took said bag to her place of work (school) and whilst trying to find something she tipped out the contents onto a table, thus a rather gruesome discovery was made. I can’t imagine she’s ever forgotten this, as I definitely haven’t…

Fast forward to now and I’m in my early 20s, training to be a teacher. (This was probably around 6-7 years ago now) She is coming to my school to do supply work for the day in a few weeks. I’m so nervous and I don’t know what to do.. I’m just so embarrassed!! I have never told anyone about this before either. This serves me right for working in my home town I guess lol. Can anyone give me any advice please I’m desperate!