not quite sure

Hi everyone, I’m new here and i just had a simple question that maybe someone knows. I’ve looked around but am not quite still sure yet. a few nights ago my girlfriend gave oral sex. Then the next night she believed she had one of her cold sores show up. do you think that this cold sore will give me genital herpes? or are the chances lower. I'm quite the hypochondriac and am quite worried. Thank you for any answers or help.