Panicking about stomach flu

My anxiety goes wild when I am sick so I am still wearing a mask everywhere. But stupidly I let myself be invited to a neigbhor's house. She told me that she needs some groceries and when I bought them she invited me in. She then said that she was on ER the other day, had a stomach bug for four days and she still isn't fully recovered. The minute she said that, I started panicking and after a few minutes I told her I must go.

We were close so what are my chances of catching it? I always have had the worst cases of stomach bug, one time I haven't recovered for three weeks and last time I went to ER. I really can't be sick with that shit again.

I googled and people are contagious even two weeks after recovery.