Exercise Tips for staying small during pregnancy

Just got my positive test on Sunday and I’m super excited to be a mommy. One thing that has me nervous is how large my bump will possibly be. I’m 4’11” and about 107 lbs as of right now. I really really don’t want to get a huge bump while I’m pregnant or gain more than 25lbs if possible. Any short girls who have experienced this with their pregnancies? What exercises should I be doing?