Starting pregnancy heavier than I want to be - advice from moms that have toned up?

TL;DR: I'm heavier than I want to be starting this pregnancy out. Have any moms not necessarily lost weight, but took up a fitness routine that put you in better shape by the end of your pregnancy or at least toned up?

So I weighed in at 5 weeks at 188 lbs. That is the heaviest I've been in close to 10 years. I put on close to 20 lbs over the course of about 2 months (the biggest weight gain I've ever experienced).

I had a miscarriage shortly before this pregnancy so I think I took to emotional eating and generally avoided physical activity. I was a pretty active person before my miscarriage (last September) and at a weight that I wasn't unhappy with. Mostly I feel like I'm flabby and want to tone up. Plus I'll be in the final trimester in the middle of summer in Georgia and I'm trying to avoid vicious chub rub between my thighs. 😭 I know weight gain is inevitable and I want a baby with a healthy weigh (obviously), but I'd like to gain only baby weight and tone up everything else. Has anyone had a similar experience or have any advice?