You're tires are barely true or your wheels are barely true?

If your tires are wobbling around but the rims remain equidistant from the the fork blades/stays, then your tires may not have been seated properly after the last flat change.

If your rims are indeed wobbling, take the bike into a shop and have them trued. Wheels on most new bikes tend to go out of true slightly in the first few days/weeks of riding and they probably just need to be touched up by someone who knows what they're doing.