How would you handle it?

I'm in highschool and went into the store to buy a pregnancy test the only checkout was a girl who also goes to my school. a few days after I find out that she went around tell people that I was pregnant, but honestly how is she gonna tell people I'm pregnant forsure without knowing, she's only assuming because I purchased a pregnancy test. Is this even okay that she left her work place and went to school telling people we go to school with? How would you handle it?