Heart rate while exercising

Kelslie
Hey everyone,
I had my first appointment yesterday and told her I was going back into the gym took a 3 week break as I felt so sick and wanted to make sure baby was okay. She said she'd rather me not do anything hug swim and maybe treadmill. Also said I need to keep heart rate under 120. I get on the cycle or treadmill I'm 155-165 easily in a minute or two. I've always had a higher heart rate from adderall. I of course am not taking it. 2 months ago the heart rate monitor said 190! So what is the safe zone! I want to work out!!!