Hi Hun, I go to the gym 3 times a week and I also do aerobics. My instructors told me that's it's fine to carry on at the Same level you have always done. I took it a bit easier during tri 1 just in case! But I'm exercising as normal now unless I'm having a knackered day, then I take it down a notch!
Best to speak to your instructor and also listen to your body. You'll know if you're doing too much. X