Good day i took my son for his mesurements on 05/10 they said they are worried about his head cir 46.5 he is 6 months . should i be worried?

Maybe/not: Any measurement is a point in time and must first be compared to the other measurements (Ht/wt) and the pattern those measurements create over time. It is at the larger end of normal for age & would be worrisome if the kid changed moved from average to large over a few months, or if all other measurements were average. I usually measure both adults, since predicted head size can be genetic.