Hye guys..need to ask something with u guys..

this is the situations. I have unprotected sex with my gf last wednesday 09 april. The things that I'm worried is she didnt remember when is her first and last day of her period last month. The only things she remember is it finished at around end of last month, which is either 28,29, or so on. and she said may be she started her period on 24 march.

I didnt ejaculate inside but i'm afraid with my precum..we didnt do sex the day before.

So the next day I've ask my gf to eat Postinor (around 33 hours after we've intercourse). So what are the chances for her to get pregnant? We're so worried....