Why would you suspect herpes or HIV? Do you have risks for those?
A lot of cases of hives are considered ideopathic, where the cause is unknown. HIV and herpes aren't known to cause hives. Herpes would only give you oral or genital symptoms - wherever you had the infection. It's not a systemic (meaning full body) infection.
Stress can also cause hives. I mean, with everything going on, it seems silly to ask if you're facing more stress, but are you?
You might have been exposed to something during those two weeks that you weren't even aware of that was causing an allergy. You might also never know.