Is wearing shoes that don't fit you bad?

My running shoes i think are to small now, i mean they don't feel too uncomfortable, i'm just a little concerned that it's bad that wearing shoes that don't fit you, could hurt you. Does it make your foot from not growing? I only wear them for PE, other than that i got my Track & Field shoes which i use for practice, and my regular shoes. So you think wearing 1 shoe that doesn't fit will make a big difference? The tip of my toe is barely touching the tip of the shoe, just to let you know.I'll be wearing them for only 3 more months, so i think maybe i could withstand it, plus i just got Track shoes, and i don't want my parents to pay to much money for my shoes, even though i'ld pay for them, i'll buy new ones in the summer time for sure.PLEASE HELP ME. I need help. THANK YOU