I'm 31 weeks I'm was belly sleeper as well. I mow sleep on my side with three pillows under my head one to support my back and another between my legs.. it's very uncomfortable sleeping without on at this point.. I miss sleeping on my tummy but it's impossible to do now lol...
Get a pregnancy pillow! I was the same way and now at nearly 33weeks the only way I can sleep is with the pillow! Truley a life saver.
I'm almost 25 weeks and I sleep on my side with covers or pillows under my belly and it helps. I used to love sleeping on my back and but when I got pregnant I decided to start sleeping on my sides so that I would already be used to it and comfortable with it before it was a must. I also prop up on my back when I'm just relaxing. I hope this helps! Congratulations and good luck!
As you get bigger, believe me, sleeping on your belly will NOT be an option because it will be impossible, lol. I sleep with a pillow right behind my back, a long pilloe to support my belly, a nice cool pillow between my knees, and then a nice, firm pillow to support my head and neck.
Get body pillows once you get bigger you're going to need them
You can sleep on your stomach until it gets uncomfortable and your uterus is small enough that you can sleep on your back at the moment. Sleeping on your back is discouraged though because the weight of your uterus compresses your inferior vena cava as it grows. Your side is the best and ideally the left side, as it's best for circulation.