tampon can barely fit in me

I'm 15 and I tried a tamppn for the first time yesterday (playtex sport) and it was a little bit painful and totally uncomfortable to put it in. It won't be for awhile, but when I do meet the guy I want to lose my virginity to, how am I going to be able to do that? I can't even fit a small tampon in a couple inches up, how am I going to even have sex? Does anyone else have similar experiences?