Condoms

So my boyfriend and I use condoms everytime we have sex and he pulls out with the condom on. Last time we had sex, there was a wet spot on the bed. I checked the condom and there were absolutely no leaks or tears. So the only way that something could have happened is the condom rolled down off my boyfriends penis, but he says it didn’t. Could the wet spot have been from me and I’m just being paranoid. Cus it didn’t look lie semen. It was just a damp spot. I’m just trying not to freak out