My coworkers are convenced I'm pregnant

So last week I told my coworkers I wasn't feeling so hot. Bad heartburn, pain in my lower back and sides, and a little nauseous. Since then 4 of them have asked if I'm pregnant, we'll I had my period 10 days ago so I said no, but they won't let it go. Well I get to work this morning one of my co-teachers said over the weekend she had a dream about me being pregnant with twins and she said she's gonna prove me wrong and buy me a test on Friday and prove I'm pregnant. We joke around about it because I keep telling them they're gonna jinx me lol