Your two doctors disagree because deworming in the third trimester is a genuine judgment call, not something with one fixed answer. This needs deciding by whichever obstetrician is actively following your pregnancy, with your reports in front of them.
Next Steps
Take both opinions back to your primary treating gynaecologist and let them make the final call, rather than deciding between the two views on your own.
Health Tips
Mild anaemia in pregnancy is common and manageable, but a treatment decision this close to your due date should stay with the doctor who knows your full case.