Hey dear. ..never sleep straight during pregnancy. ..till 6 mmths left side n then right or left. ...mere gynec ne btaya tha ki straight sone se baby ko breathing me prb hoti he. ..

Do excersis.

That's y it is not advisable to sleep on your back plz sleep on your sides n mostly on left it will really help you, sleeping on left side will also help you to digest your food easily so that you don't suffer from heat burn etc

https://www.babychakra.com/learn/2774-sleeping-positions-during-pregnancy-to-help-reduce-the-discomfort

https://www.babychakra.com/learn/2194-the-right-sleeping-position-during-pregnancy-take-this-advice-to-get-some-sleep