Weight loss while pregnant

Haley
Hello plus sized mamas! 
For those of you who have lost weight during your first or first and second trimesters how have you done it? I am currently 4 weeks 4days. Technically my second pregnancy as I miscarried in July. Obviously I'm very nervous and would like this pregnancy to be as healthy as possible and a success! Currently weigh around 310-320 at 5'8. Any tips for weight loss or atleast not gaining?