37 weeks doctor requested growth ultrasound

Kim • 1 daughter on earth🎀 & 1 daughter in heaven🕊

Just went to my 37 week check up and the doctor said last week my stomach was measuring at 36 cm and this week I'm measuring at 42 cm. She said that's a huge jump and wants an ultrasound to see if there is too much fluid. If there is too much fluid I may need an induction. Anybody had this happen, or knows anything about this? What the possibilities are for my stomach measuring so much bigger in 1 week