Why am I so out of breath?! I’m 23w today and for the past 2 weeks I get really out of breath when I walk anywhere. I get out of breath walking up the stairs.

I am not overweight but I have but on a bit of weight in pregnancy but I’m not huge or anything and I try and be active 3-4 times a week.

What’s causing this? Am I just so unfit? I read that during the later stages of pregnancy you will be out of breath as all your organs are shoved upwards but I’m still in my second tri.