I had a one night stand with a girl, who I didn't know at all. She wasn't very nice and told me after I "did my business" to leave instantly and that she didn't care about anything I did or said, which I wouldn't mind if it was just sex but for some reason I have started developing feelings for her but I know she wouldn't want to see me again especially not sober (only tipsy, there was consent). Feeling pretty poor about the whole thing, mainly the immorality of it and the fact it was my first one night stand, also the fact I know she doesn't care at all about me. I also think I might have got her pregnant/ she might've gave me an STI. My flatmates and friends are calling me a "lad" but I fell like an idiot and that I've been used for sex, debating contacting her but not sure that's a great idea.