Is this normal for my heart rate?

I am 39 weeks pregnant, and have c vid. I’ve had it since at least the 5th of this month as that’s when my symptoms started. I tested positive for it on the 8th because I went to the ER after baby decided to be stubborn and not move.

Today, and last night, I noticed as I was washing dishes I felt kind of faint. I checked my oxygen and it said it was fine, but my pulse was staying 144-150.

Until I sat down then it went back down to 70-90. When I got up slowly it still went back up to 144.

Is that normal? Or should I be concerned?