Lol, I just said I've been with her for 2 years...
OK well:
1. When this is the first time, something like this happened, then I think she should understand that it was only a mistake (well I hope so, because you are together already for 2 years), but:
2. MANY girls are a little bit wiered lol. I mean you do literally nothing, but the girls need to overstate and act like you killed him.
My advice for you is, when it happened today, wait for the next day(s) and try to talk again with her, and if she really loves you then she wouldnt just ignore you after 2 years for something like this.
Good luck!