not at all. you sound young, if i was you id be careful when messing around. but just to let you know theres no possible way to get pregnant unless he puts his penis inside your vagina and ejaculates.
next time , have protection and be careful - and have a planned pregnancy
If there was a decent amount of pre-ejaculation and ejaculation on your vagina it might be possible, but from what you've described it's unlikely. Unless you're prepared for possible pregnancy it would be best to either entirely avoid situations like these or use protection anytime his penis might be within the proximity of your vagina.
It can happen without being inside of you. If any of his ejaculation or pre comes in contact with your vagina it is possible. Sorry to send this the other way but it can happen.
Read the posting titled "SPERM" and this can help answer your qustions. I had to go back about 26 pages to find it but I think it will be helpful for you. Good luck :)