Your EDD according to LMP will be December 17,2021..your scans are showing more or less same gestation age.scans do defer in gestational age the more you approach the third trimester.with history of two previous C sections it's most advisable to undergo elective C section two to three weeks before EDD i.e after completing 37weeks.
Next Steps
get counseling with your obstetrician and require follow up scans for baby parameters and scar strength