confused, need answers please

hello, my question is this. Two weeks ago my girlfriend had an upset stomach and had diarreah. she then developped a rash like a heat rash. So we went to the doctor and he did a swab test and it tested positive for a yest infection on and around her anus. He did another swab for the herpes virus. she was given medication for her yeast infection. a couple of days later it healed up. then yesterday morning we gat a call from our family doctor stating that she tested positive for herpes and she needed to get medication for this. more than two weeks had past and no one contacted us. we whent to outpatient yesterday for me to get tested but the doctor told us the only way to do a swab test was during an outbreak. he found it very strang that it took so long to get the results of the test. I have type 1 or cold sores, she has never had cold sores or type 2 except for two weeks ago. My concern is that we have never had anal sex and i have never performed oral sex on her anus. so how could she develope herpes. I blame my self because i am the only one that she has had unpretected sex with. I have performed oral sex on her but not in the arrea of the outbreak. Could she have gotten a false positive or could i have given her the virus. We are very carful when i have a cold sore. is it possible that i didn't notice i had one and i gave it to her . please and thank you for your fedback