ATT Text Message Question iPhone 3G

I bought a new iPhone 3G yesterday. I did not get any of the ATT text plans. Does anyone know if the "View My Minutes" (*646#) is a free message from ATT, or if it will be charged on my next bill as a text message? The registration text messages I received all said "FREE MESSAGE" on them, but this one did not.

I checked ATT's mywireless website, but could not find an answer there.

Thanks,

Rick