I'm going to guess your son is over a year old an old enough to do some things with you that you used to enjoy as a couple. That being said it still takes work. I have 4 kids, but only 1 with my husband and since our relationship started with the big kids being a part of it, they didn't have the same effect that the baby has had. I stay home, I'm up at 645 with the baby, clean up the house, get the big kids up, cook breakfast, homeschool them, have lunch ready for when hubby comes home from work on break (only instead of getting to catch up with him the baby is generally crabby and I'm in need of a shower, or 5 minutes to pee alone, and of course hubby missed his son) then it's more cleaning, more baby care, homework for me (i'm working on my degree) and starting dinner. All in some (futile) hope that everything will be done when hubby gets off work and we can actually spend some time together.
Only thing is by the time dinner is over and cleaned up the kids want family time, the baby needs to get to bed, and I'm so beat I just want to relax and of course hubby had a long work day and wants some time too. So he sits on his computer and i go up to bed alone and we do it all over again the next day.
It takes so much work and a lot of times that work seems to be for nothing, even when we do things as a family, with 4 kids we don't get to enjoy it together as a couple. We used to be a great team but now it seems like we can't do anything together because someone always has to have the baby (and since he's not handy, and can't even use the bathroom if he's alone with the baby, I feel stuck doing it ALL)
That being said I think it's normal. Relationships go through periods of time when things are rough and the flame dies, unless you go out of your way to keep things alive. talk t your husband, see if you can't get on the same page about a compromise to fix things. My hubby is a nightowl and I obviously can't be anymore, but since he likes to stay up anyways we agreed that after the baby goes to bed (between 730-830) that he will spend time with me until I go up to bed (10 or 1030). Or if I need/want to sit on my computer or whatever he comes up when i go to bed and we lay there and talk like we used to, about whatever stupid stuff comes to mind and then i go to sleep and he comes back downstairs. And we've done bigger things, once a month or so we get a movie and after the kids are in bed we curl up on the couch together, like when we used to date, or we get a sitter and go to dinner, and a lot of times we even take the baby and run errands together, just so I'm not feeling trapped alone (or with the kids) at home. But again it's something we both saw was happening and we FORCE ourselves to try.
And I may be off base, but chances are you don't much like your husband right now. You may feel used or under appreciated, maybe there is some resentment there ( i know I feel all these things often enough) but if you can deal with some of those feelings the intimacy comes back.