C section- plus size

Sara

At my 36 week visit today my ob explained why I'm having an ultra sound next week at 37 weeks to check the size of my baby. If it is determined his shoulders are too large they want to schedule a c section. At my 32 week ultra sound he was measuring average no too big not too small. Is it just because I'm overweight they assume my baby will be big? I hope I'm not pressured to have a c section just because of my weight.