Sex men v. Women

Why does it seem like I want sex more often then my bf?? I've lost my virginity years ago, and I just recently took my boyfriends a few months ago.
​He's always up for it, believe me, it's just that he uses the excuse "I'm out of condoms" whenever we're on the edge of doing it! -.- it pisses me of 
​Like if he wanted it that bad he would buy condoms and be stocked up, but that's like the 4th time he's told me. I think it may be me, maybe he doesn't want to do it with me. 
​Idk girls what do you think??