With my first my dog was like that. The further along I got the more attached he got. I think they sense you can do less and less and want to take care of and protect you. After I had my daughter heswitched to her. From the day she came home you will see in every picture him right there watching her, trailing whomever was carrying her or peeking into hER crib/portacrib to make sure she was ok. He was never more than two feet from her those first 16 months (he passed when she was 16 months old :-(. I wouldnt stress he just wants to protect you and baby.
I was just curious.. I've already went into labor 2weeks ago and they stopped it but he didn't want anything to do with me the day that happened and it took him a few days to come back around. I love that he being so sweet and cuddly. Lol
My dog was actually the first one to know I was pregnant, I couldn't figure out why my normally aloof dog was super cuddly and wouldn't leave me alone...turns out it was it was because I was pregnant! As a dog trainer I have researched it a lot and dogs can detect the slightest hormone change in you. If he has he been cuddly then when you went into labour he backed off, he might be scared for you/not like seeing you in pain, he may not understand what is going on, as a male he may want to give you space to have the baby as females (dogs) are usually alone when they give birth so he might be doing that for you or he might know that baby is coming and be worried about it taking his spot. Its all VERY normal, just try to reassure your dog that you still love him and he is still important to you and he will eventually understand.