I had cryosurgery and the mole became a blister and seems to have a yellow pus now that is oozing. Is this normal?

Freezing tissue causes a reaction where fluid often collects under the surface of the skin.  This is usually a thick yellowish fluid called serum. The surrounding area is usually slightly red but localized around the site.  It is unusual for it to become infected.  However, if the redness spreads, becomes very tender  you should have your physician check it.