I went through that around that time but mine went away about a week later. Hang in there! Hopefully, you'll feel better soon.
I had to give up playing my clarinet til after the baby due to not enough oxygen.to go around for the both of us and the instrument. It's sad. I gave itup about 3 weeks ago finally after trying ans failing. I'm 22 weeks now.
I went thru that around 18 weeks or so i was thinking omg im.not going to make it if i cant breathe this soon :o but it went away in a week or 2 :) now im.27+4 and i feel great sometimes i.get winded but thats because im trying to keep up with everyone while waddling lol