Hellobee Boards

Lots of pillows. In particular I had a squishy pillow that wedged a little under my belly and I hugged to my chest, plus a firm pillow for my head. I would bring those two pillows when I traveled bc it was the only thing that worked.

No advice, but sympathy. I'm mostly a back sleeper and occasionally sleep on my tummy, so the transition to side sleeping has been rough. It really bothers the shoulder and arm on the bottom, they don't like the pressure and I feel like I never know what to do with them so it's hard to get comfy. The only thing I've found that helps is to angle my body so I'm sort of halfway between my side and tummy, with my body pillow supporting most of my body weight and just the front edge of my shoulder and hip on the mattress (does that make sense?). But I'm not sure this will work as my belly gets bigger.

ETA: I think side sleeping is also giving me neck wrinkles Not happy about that.

The snoogle was the single best purchase of my pregnancy. It ha helped me get a good nights sleep since 20 weeks - I only realized how valuable it was when I slept in a hotel a few weeks ago without it!

Echoing the advice of lots of pillows!
I'm a side-sleeper as well but pregnancy side sleeping was a whole different ball game. I ended up with my usual head pillow (which is really two pillows), one between my knees, one partially under my belly that I could hug as I slept (and rest my arm on) and like @Adira: one behind the small of my back so I could put a little weight on it.