Dental work while pregnant?

Hey ladies, i am having an issue and i could use some help.. I have a couple small cavities that I need to have filled, one or two that need crowns, and to have my wisdom teeth taken out..

My problem is that I am VERY afraid of the dentist, and I always have to use the gas stuff (that goes on your nose) and even then I am still really nervous. I am 22 weeks pregnant, I've read that the gas that they use isn't safe for the baby, and laying on my back for longer then 5 or 10 mins, makes my stomach cramp up and it's very uncomfortable.. So, I don't know what to do. I know my wisdom teeth and the crowns can wait until after the baby is born, but I'd like to get the fillings in as soon as possible..

I've googled this a few times, but, I haven't found anything that fits my situation so, I need others input please!