E.B.
MMR is a live vaccine (at least, it was for my son 6 months ago) and therefore can sometimes yield weird results. My son actually broke out in measles and was technically contagious for 2 days! It didn't bother him at all, and it mostly made me laugh--he had this rash on his belly that was a mild case of measles! But...I still called the doc, just to be sure--putting a call in certainly can't hurt anything!