Breathlessness/cant catch my breath 27wks + 5days

Aw

This last week I’ve been noticing I get out of breath, sometimes for no reason like last Wednesday I was literally sitting at my desk at work and got really warm and faint all of a sudden and felt like I couldn’t breathe. I had a bad uti which I’m still recovering from and I’m back to work today I walked slowly to the bus station about a 10/15min walk and I’ve been on the bus for 10mins and I still haven’t caught my breath. I see my midwife on Wednesday so I’ll bring it up then but has anyone else experienced this? Also I’ve never had these issues, I’m usually relatively healthy small and slim. My bump isn’t too big either, it’s definitely grown a lot the last few weeks but even then no one believes I am pretty much 3rd trimester. I’m thinking it’s maybe because she’s not popping out much she’s taking a lot of room at my lungs? I’ve no clue I’m a FTM 😅