Has anyone been trying to keep up their fitness regime?

I was working out 3/4 cycling and fitness classes before pregnancy.

With the extreme exhaustion, nausea and dizziness when working out I'm struggling to do something once a week.

Hoping to do more as want to be fit and healthy for the delivery and don't want to lose muscle tone.

I didn't realise it would be so difficult. I thought pregnant women were exaggerating but struggle is real.

I've been reading up on what's safe and what isn't.