Oral sex

What are the chances of getting an sti/std in these circumstances. I know I didn't get anything in my mouth but would about on my vagina? So I went out to give this guy head at night and we went behind a park. He took my shirt and bra off and half way through he told me to take my shorts off and they were half off, still had underwear one. And I was on my knees on the ground. And when he did cum he did it on face/in my mouth that i remember anyway. Even though I had underwear on could I have got hpv on my vagina? Or herpes or anything?