I m 22 weeks and have gained 30 lbs so far on my first pregnancy.

I am getting nervous as I want to be healthy and have difficulty walking due to swelling ankles. What are you suggestions for helping me not gain any additional weight until need be towards the end of pregnancy. Any ideas for pregnancy approved exercises, etc?
Thanks in advance!
Re: How to maintain weight
diagnosed with unexplained infertility, regular cycles
Baby #1: ttc naturally for 3 years, 6 yr old daughter
Baby #2: ttc naturally for 2 years, 2 yr old son
Baby #3: ttc naturally since August 2016