Is this just a coincidence?

Well yesterday I went to my boyfriends house and we had sex together for the first time. We both felt fine and then my night was good. I came home and ate the same dinner and dessert that my family ate and then I felt fine when I went to bed. I woke up at about 2 in the morning and my stomach hurt like crazy and I ended up throwing up every half hour and I am still throwing up a little bit. And at like 4 in the morning it started coming out both ends (sorry if thats to much information). So I just find it weird that I felt perfectly fine and so did my boyfriend and nobody else I was around has been sick and I got sick. So could it have something to do with the sex? I’ve never heard of anything like that, but I don’t know.