Can a pcr hsv test that was a swab test meant for genitals be used on the mouth and if so would the lab results show it was the mouth swabbed and not saythe vagina. someone has done a pcr test but said they did it themselves and have read about this?

The test can be done anywhere there is suspicion of HSV infection: genital ulcer, mouth, anus, or even certain skin lesions. However, HSV PCR testing rarely is useful to diagnose herpes in absence of symptoms. It should be done only on a blister, ulcer, or other lesion that might be herpes. PCR should be done ASAP after onset; older or healing lesions often test negative even if it's herpes.