Is there chance that i could be pregnant?

ok so im 15 and like a week ago my boyfriend tried to get me to hae with him. i agreed but then before he completely got inside me i told him to stop. he said it was just the tip of his that was even in. he didnt have a condom. i didnt think of this at the time but i have heard before that even something like that could get you pregnant tho. i really need ome answers here because i am really scared. i like to think to myself that tit couldnt happen because we didnt really have and i never ever have before, but im scared and unsure about everything. i need some answers really bad. please please please help me.