woah, hold the **** on, got something URGENT to say here ok? cus i have personally had this happen to me.
Now, it could be to do with anything, from periods, to resentment, to family issues, to whatever, but i have one piece of advice;
Leave it.
I dont know if this girl is your friend or gf, give her space. days, weeks, a month even, if she does not want to be approached, then dont approach kapeesh?
now i know im gonna get tons of people goin "no, communication is cornerstone to a relationship" and i cudnt agree more, but from personal experience its wise just to leave it and not be involved for a few days. god, i wish i had buddy. she'll come around, or not, either way its her choice, just dont push the issue.
sorry about the intensity but i had my world cluster ****ed by sumthin like this cus i tried to talk to a girl who was ignoring me and **** kicked off. just trying to pass on the wisdom