Is it okay to lose weight while pregnant

Amanda • 24 yrs old. Mommy to a beautiful 3 year old he is my pride and joy. And now we are expecting our 2nd on july 25!
I am about 30lbs heavier than before my first child and slightly over weight anyone know if it is OK to lose weight while pregnant as long as baby and belly grow? I really don't wanna b 30 lbs heavier again BC then I will be really overweight