Again, not a Dad, but I just had to second what everybody else has said. You need a support person with you who will be there for you and help you while birthing, not someone who is putting themselves first. I had both my Mum and DH with me and when things started to go wrong DH panicked and was running around like a headless chook while Mum was the one to calmly talk to the midwife and talk about what my options where. So sit DH down and calmly tell him how terrible he was last time and this time you want to feel more important than Harry Potter so your Mum is coming in unless he can give you an iron clad guarantee that he will devote 100% of his attention on you.

Good luck and be firm!

PS hate to be pedantic but I can't help it, it's actually only 38 weeks of real pregnancy (the first two are the two between the end of your last period and ovulation) and there are 4.33333333 weeks in a month so 38weeks = 9 months. Unless you go right over of course