Hello girls) I'm 39 weeks pregnant, and according to ultrasound, all …

Hello girls) I'm 39 weeks pregnant, and according to ultrasound, all dates are wrong ? My belly hasn't dropped yet, and there are no signs yet. Has anyone experienced this? Twice a week in the 2nd or 3rd trimester, my belly feels tight. The doctor checked, she says that the cervix and birth canal aren't ready yet...