8 months pregnant, dog starts pooping on the floor again

Hank, my german shepard/lab mix, is 3 years old and we have had him for a little over two years. We got him from the shelter when he was 9 months. He was mostly potty trained then, but has always had the occasional accident. Lately it seems like it is almost every day though. The only time we had a nice break from the constant coming home to find poop on the floor was recently when my husband was out of town for 4 days. Those 4 days not a single accident or any bad behavior. That's what has me so confused. I was thinking that maybe he was sensing the changes around the household getting ready for the baby, but I don't know why he would have been so good while my husband was gone. I am his obvious favorite and I believe the alpha (I have one older dog who is a perfect angel), and I am wondering if this is related to Hank being jealous of the upcoming baby and my husband. He is a very jealous dog and barely lets me pet my other dog without walking between her and I. I feel I should mention also, that it is my husbands responsibility to take care of the dogs in the morning, but I obviously took over while he was gone. I'm wondering if me being the last person Hank saw had any influence in his behavior while we are gone. If so, should I somehow figure out a way my husband can be the alpha instead? I really need help. I don't know how I am going to handle a newborn and this dog's disgusting mess if I can't get him to stop.