I had a belly belt that also served as back support during my pregnancies. I don't know the brand as I passed it along, but I think I saw it at Babies R Us. It had a front panel, back stretchy panel that velcroed together at the hip. There was an elastic band that ran across the top of your belly that I cut off because it dug in.
It was the single best pregnancy item I owned!
Not only did it help me with pulling belly ligament pain to help support my growing belly, but it also helped my back by preventing my belly from pulling my weight forward.
Finally, I used it postpartum IN THE HOSPITAL almost immediately after my kids were born. There is a small window of time post partum where all the hormones that "loosened you up" to let your body open up to pass the baby will reverse and "tighten you up" and help your organs to go back to where they belong. I wore the belt 24/7 and only took it off to shower. I wore it for about 1-2 mos post partum. And it really worked!
I can't tell you how many people commented on my flat tummy postpartum. Sometimes I was wearing the belt under clothes and they didn't know! Other times, I was already done wearing it and things were back where they belonged.
The logic is that when your body is tightening back up due to hormones if you "push things back into place" that's where your muscles and ligaments will hold them into. Therefore your "belly" isn't really your loose organs that have slipped out of place.
It doesn't cure belly fat, but that too will go over time. My third child is almost 6 mos old now and I only have about 10 lbs left to loose. I am back to my prebaby weight from him, so this last 10 lbs is to get back to prekid size. My belly is EXTREMELY flat, with only a hint of that last 10 lbs - but this is all done WITHOUT working out/gym.
Good luck on this preganancy! I'd check out eBay for a used belt, but a new one would be a wonderful gift to yourself too.