Post baby weight

So I pretty much was pregnant back to back I had my first son and nine months later found out I was pregnant with my second son. After having first son the weight flew right off... I’m now 18 months postpartum and the weight won’t budge!!! Who else is like this... I thought for sure running after and caring for two babies would surely make the weight just melt off... how is it with baby #3 ... anyone?!? Tips tricks lol... I know working out and eating right help and I do but still feel like it’s just lingering