I'm 21 weeks and still sleep on my Tummy but is definitely getting less comftable now!
Get a pregnancy pillow or I use a regular body pillow. Have one leg up on the pillow the other on the bed so you are wrapped around the pillow (if that makes sense) it will make you half on your belly half on your side.
I'm 33wks and still wake up on my stomach in pain. Crazy right??
I'm a tummy sleeper myself and a pillow is really helping. It took a couple days to get use to it but I'm almost 20 weeks and I can't sleep on my stomach anymore and don't even try. I started having trouble around 14 weeks as well
I am a stomach sleeper too. I swear I haven't had a full nights sleep since I found out I was pregnant (I'm 19 weeks so that's a loooong time). Get a pregnancy pillow. It is definitely helping me.