There's not enough detail to confirm whether what you're seeing is normal, a mechanical problem, or a user problem. Since the bike is brand new bring it back to the shop, and let a mechanic take a look and test ride and see if you can manifest the issue in front of him, so he can either fix or explain it.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.