If one were exposed to genital herpes 3 weeks ago from making out w woman who has it. when would body aches appear if they catch it? no other symptoms.

Herpes infection: Genital herpes is very contagious. At 40, assuming you have had other sexual contacts, it is present although perhaps not giving you symptoms in all likelihood. Stress and fever as in influenza may bring out an episode, but at this point if you had contact with active herpes sexually, you should be having symptoms, unless you had previous herpes and have antibodies present.

Probably home free: The average transmission risk for genital herpes, if partner has HSV2 but no active outbreak, averages roughly once for every few hundred to 1000 exposures. If HSV1, the risk is lower still, but both higher if there was an active outbreak at the time. Body aches alone would almost never be the only symptom. Given both low odds plus lack of genital blisters/sores, it's very unlikely you caught it.