Hello
Welcome to health care magic.
There are two possibilities in your case.
Firstly,
herpes simplex is an infection which can present either with or without symptoms.Those without symptoms can infect other through direct skin contact,genital or oral secretions even if there are no visible skin lesions.They can be diagnosed only through serological blood tests.
Though
incubation period of HSV is 2-11 days ,but as infection can be asymptomatic ,you cannot say which of your partner gave you the infection.
Second possibility is if your recent test was done by
ELISA antibodies ,you can get it confirmed by Western blot test to rule out any false positive result.
For prevention against getting or transmitting infection,the measures you can take is,
-Avoid sexual contacts where you are unaware about patner's status.
-Using condom
-Involve in monogamous relationship with uninfected partner.
-You may visit
STD physician for course of valacyclovir to reduce chances of transmission.
Hope this information helps.
Wish you good health.