Hi, I Accidentally Rubbed And Penetrated My Girl Friend Once

Hi,
I accidentally rubbed and penetrated my girl friend once through her underwear, probably not deep enough. She was in a lot of pain and soreness but there wasn't any blood. However, this afternoon she told me she has brown blood coming out when she went to the restroom, the kind of blood she has on her periods, but it is 2 weeks early. I'm worried I might have broken her hymen, but she assured me it doesn't seem that way. Have I broke hers? What should I do to care for her?
Thank you.
Ben.