First time using tampon and bleeding during sex help?!?!?!

So a couple weeks ago I had my period and I used a tampon for the first time ever and since I used the tampon whenever I’ve had sex I’ve bled and I don’t understand why or how to fix it I thought it was because it always hurt a little when it first went in but I only started bleeding after I used the tampon so idk if that can have something to do with it (im trying to get as much advice as possible im 16 and I don’t want to tell my mom I’m sexually active)