stomach sleeping

This is my 2nd pregnancy, 1st child. My last one ended at 9w5d with a mmc. How long were you guys able to sleep on your stomach? Especially with 1st pregnancy. I woke up sleeping on mine and it wasn't uncomfortable which worries me that my baby isn't progressing. I'm 11w5d. I haven't really had a lot of symptoms this pregnancy, but at my ultrasound at 9w5d the baby looked amazing and had a strong HR and was dancing around.