I had this issue and went to the ER they told me I most likely had what's called costochondritis which can be caused by straining your chest or having an infection. Really scary if I got out of bed to go to the bathroom I experienced labored breathing. Didn't experience any other symptoms other than breathlessness and mild chest pain. Make sure that your not lifting anything heavy
I am only 15 weeks pregnant and very breathless at times. I can't even go through the song twinkle twinkle little star for my daughter!
I have that problem but I'm 35+2 it gets a lot worse believe me lol
It's normal, you have more blood circulating then normal causing extra work for your heart and lungs. Plus your growing a human so that takes a lot out of you.