Sleeping positions

I’m 16 weeks pregnant and can’t stop sleeping on my back! I’ve tried for weeks even got a maternity pillow but don’t seem to be able to control how I’m laying.

This really worries me as I’ve heard it can hurt the baby?

I’m pretty sure 7 years ago I slept on my back with my first born. As I had no idea.

Any suggestions or advice welcome

Thank you xxxxx