BLOWJOBS

Every time I give my boyfriend head, he says things like "omg baby you give the best head" and he moans it, but I always felt like I wasn't very good at giving head, so how can you tell if he is just trying to make me feel better or if he's really honestly enjoying it. Cause I know guys can fake it, I never make him cum by giving him head, he lasts forever even just having sex.. I would have to do it for a while..  a couple times he said while I was giving him head, "omg you're gonna make me cum" but ended up not and just wanted to have sex with me instead.. so I just want to know if he fakes it to make me feel better or should I be more confident about giving him blowjobs? I just always feel like I'm doing bad when I'm going at it lol