Is it hard to breathe because of a stuffy nose or heartburn or just general discomfort?
I have some breathing problems at night. For me, it's due to the rapid pulse and chest pounding from low BP and increased blood volume. It's hard to catch my breath. I think it's worse at night because BP usually drops lower when a person lays down, which probably means my heart is beating even faster to pump blood. My OB said this is very common during pregnancy.
Don't know if that helps.