Is he falling out of love

To make this as short as possible, we were the couple that always had fun, always made eachother happy, danced in the car, and made love. He took my son in as his own. He loved him deeply. Things were always good we always talked everything over... fast forward Here we are in our 4th year of being together and we’ve had one baby and are pregnant with another. So on our 3rd kid (technically) together. The past month or so, he doesn’t cuddle me, we don’t have sex, and if we do it’s just a quickie, we don’t have any intimacy, 90% of the time we are sleeping in different beds or hes sleeping on the couch, we still have fun sometimes but nothing like before, I’ll admit I have been more uptight and moody but idk.. me being the paranoid girlfriend I am (not my proudest thing) I went threw his phone. Absolutely nothing. So what is it? What’s going on? Everytime I bring it up he says he hasn’t noticed a change and maybe I’m just over thinking it, but I just feel differently, right now he’s laying in bed and I came into bed to try to cuddle him while the kids are napping and he just rolled the other way... am I over thinking it? I just feel shattered inside and maybe it’s the pregnancy hormones but something feels off but he doesn’t notice or won’t talk to me about why..