Anyone else having less sex?

Hey guys, this is my 3rd month ttc and I'm getting really frustrated. Not because I'm not pregnant yet, but because my SO has been wanting sex less now that we're trying. We still have sex, just not as often as we shoud (or as much as I like). Last month we didn't have sex at all during my fertile week, and this cycle I'm half way through and in the mood and he's not. I've always had a higher sex drive than him, but now that we're actually trying its like 'hey, this is the time to make a baby!'. On top of that I miss the intimacy. I know he's not cheating or having doubts about a baby-we are very much in love. When I bring up wanting to have more sex he says he just isn't as in the mood as much as me and he doesn't want to lose our spark. I know it makes him feel bad, and I don't want to pressure him. I'm just really frustrated. Has anyone else gone through this? What did you say to your man?