Hi Alison,

I'm not absolutely sure, but I think it's ok as long as you are comfortable(somebody please correct me if I'm wrong) I'm almost 18 weeks and still comfortable sleeping on my tummy most of the time. The nights I'm not, I just hug a pillow or cushion and that seems to do the trick.

I've heard the body pillows are excellent for helping you sleep as well - maybe you could check them out

Hope you get a good nights sleep soon

Bel