At 34 weeks but my bumps seems 39 weeks

Hi mummies, i am very stressed and pressured as I’m only in 34 weeks but my bump looks like im ready to give birth. Doc measured my baby size and even says it is very big. I’m scared. In 2 weeks time, when I’m in week 36, they will send me to scan again and measure my baby size. I am very stressed. Can anyone advise me if i can lose some weight and how to lose weight for me and my baby before i gave birth ? #advicepls #firstbaby #pregnancy