TMI? Ways to prevent bleeding?

I’ve noticed for the last couple of months anytime my boyfriend and I have sex I’m left bleeding afterwards. Now we do get rough sometimes but other than that I’m not sure why I’m bleeding. It’s not painful during sex and my period is fairly regular so I’m almost certain it’s not that. Does anyone know of any ways to prevent bleeding from sex? Because buying liners and pads all the time is getting expensive 😓 any advice is much appreciated!