Helppppp so confused about due date?!

Got my ultrasound results from 36 weeks and they said that the baby’s tummy is measuring 39 weeks? But that the baby is about 7 pounds and 5 ounces. I still have 3 more weeks to go and could possible induce me in 3 weeks but she mentioned that they don’t want baby getting any bigger? And in 3 weeks baby can get bigger right? They didn’t really explain to me much so I’m just curious to know what’s going on?! Doctors are horrible explaining anything to me they don’t even answer my questions..or keep me in the loop about my situation.