My heart beats funny or my chest hurts

I’m 35 weeks and occasionally it feels like I experience what appears to be random increased heart rate. Maybe not super random. I have gestational diabetes and sometimes I get an elevated heart rate from glucose spikes but I’ve been measuring my glucose levels and they’ve been fine but my heart still races. Anybody else experiencing this? I think it’s not always related to my gestational diabetes... doctors appointment tomorrow, but until then, I’ll just be wondering about this.