Clingy Toddler

I have a 15 month old and I'm 7 weeks pregnant. My son had always been a sweet, snuggly guy, but lately he is relentless. The last 2 or 3 weeks or so he loses it when I go to work, will not sleep alone and when we put him in our bed he climbs on top off me. Which is generally fine, he's still a baby but he squirms a lot too. My fear is that the pressure on my belly is not good for my pregnancy. I try to get him to stop but he's not happy unless he's laying his head on my chest or belly. He's not on the small side either, 56th percentile for weight and 91st for height. Any suggestions?! To be fair, the picture was taken today and he's not feeling great...