I am a teenage girl and three days ago my boyfriend and I were 'fooling around' in a sort, but not planning on having vaginal sex. He was spooked by a loud noise from downstairs and accidentally jerked forward when i was in front of him, which caused the head of his penis to barely go into my vagina, and he wasn't wearing a condom. i'm fairly certain only 1/2 of the head got in. It didn't feel like much, and I have never had vaginal sex, so I figured that if it went in fairly deep it would hurt and tear the hymen. He did not ejaculate nor did he previously before hand, he most likely only had some pre-ejaculate on the head of his penis. He immediately pulled the small portion of his penis (the 1/2 of the head) out, too. Is there a chance, though, that I could be pregnant, even if it was such a subtle insertion of most likely an inch?