Did anyone’s doctor recommend you to exercise? If so, what do you do to exercise? Do you do it every day?

My doctor told me to exercise because she is concerned about my weight gain. And she told me to cut out carbs and sweets. But i just couldn’t stop eating. I get hungry a lot 😅 I’m 18 weeks today and have gained 15 lbs since my first ultrasound. Im petite - started out 100lbs and now i’m 115lbs. I didn’t mind the gain because i thought, well i’m pregnant lol but my doctor seems to worry 🥴