answered Feb 05, 2011 at 07:56PM
The six month follow-up (and then a mammogram on both sides in12 months) are standard practice. The reasoning being that some things on a mammogram have a tendency to come and go with fluid retention in the breast tissue (cysts and such).
The other reason for follow up at that interval, is protection against a mammogram which may have used a different technique, and the second normal mammogram acts as a safety net for you now, and as a future reference.
It is more costly this way, but safer.