Engine popping question

I know the noobie asking another dumb question but you guys all seem great and dont mind Am not sure if this is "normal" or not, being i have only 400 miles on the bike. When its warm or cold the sympton occurs. Ill be sitting still somewhere (never while riding) and give it alittle rev. Little meaning if it would have revved it would go upto maybe 3-4,000. 30% of the time right when i give it the rev it wont rev but will pop. Sounds like a backfire but not as loud as a car per say when they do. Is it the break in period or should i really have this taken in and checked out? I dont ride the bike hard, i have gave it about 3/4 throttle in second and third from 3k-7k, never been over 8k yet. I think am more of a worry wart then anything. This thing is precious to me lol