how long does it take to shrink your gums for your denture not to hurt?

I just got an immediate upper plate last week. My dentist told it would take up to 6 months for the gums to completely be "settled". She also told me to come back as needed during the healing process if I developed sore spots. My swelling has gone down (after 8 days) so my dentures aren't hurting anymore but my jaws are aching for some reason. If you've got sore spots you should call the dentist so the dentures can be adjusted.

A lot depends on why your dentures are hurting your gums. If they are moving they need to be adjusted, If you have bone chips coming to the surface they need to be dealt with. Go back to the dentist and get checked out. There is a difference between denture related pain and extraction pain.