Anxiety attacks or something else?

Asmom

Has anyone else felt like their chest was closing in and they couldn’t breathe? Idk if it’s anxiety because of the pregnancy or if maybe it’s because I’m laying on my back and I’m 23 weeks pregnant. Please help?! I was told laying on my back and stomach were very bad at this point but sometimes I unconsciously find myself there and I turn on my side, but the feeling is still there just slightly less constricting I guess.