Braxton Hicks? Or something else?!

I am 26 preggo with mono-di twins. And I'm not sure what I am feeling. This is my third pregnancy and I have no medical issues and I am healthy as can be. No history of heart problems or anxiety, etc.

It feels like a nervous-like, heart palpatating, lightheaded feeling. At first it only happened when I laid on my right side, but now it's whenever my stomach gets hard...no pain though...so I'm assuming that's Braxton Hicks, right? Ok...but what is the weird feeling following it?

Now I know I work way too much, And I'm on my feet 8-9hrs a day, but I am not in a position to stop working just yet and I don't want to use up all of my maternity leave before the twins get here! I don't see my high risk until Friday...but I'm starting to worry bc that feeling is happening more frequently!! Today...4 times. Is it just Braxton Hicks and Am I worrying too much? Or is there cause for concern?