My 3 weeks 6 days old chicks are sneezing! not a lot, just enough to notice. They were a little at the beginning, and i payed no mind. But just now when i went to check on them before i went to bed, one of my Gold Stars woke up, and sneezed, a couple times in a row then 'wiped' her beak on the shavings. They are eating, drinking, peeping, running around, everything a chick does. No mucus or anything, just a sneeze. I'm i too worried?! HELP!