Dads can experience pregnancy depression too. I have experienced it when and after my wife was pregnant.
It all comes down to our level of security. Support him physically, emotionally, spiritually anyway u know how. Because no matter whose at fault, nobody will be happy if things go sour.
He knows you being pregnant is very hard and is very difficult/near impossible to show him care and affection when you are lugging a 20lbs weight on ur hip. As long as he sees u trying ur hardest, he will be more understanding towards u and ur family.
Rae