Was this a string bet?

[Hosayif]

I dont know where to post this, so move it if necessary.

The other night i was playing with a couple people in a NL holdem tournament and it was folded to me so I announced raise. I brought out the hand that was already holding chips and stacked them out to find that with those i was only raising 2x the BB, so i went back for more. At no point between there did i have even the slightest hesitation or try to get a tell, but this kid said it was a string bet and the kid running the game agreed and made me pull out my bet. Was this a string bet or not?