Yes, it will get worse not only due to the engine vibration. Consider factors like sudden weather temperature changes, opening closing of the hood and doors and the constant wind pressure.

I have experienced this with a small 'mungo'-sized chip. In 5 months time it suddenly turned into a big spider crack extending from left to right.

Better look for an immediate replacement or surplus because windshield spot repairs is not a guarantee to stop the crack from spreading(besides i think it is quite costly too!).