Hello,
Without examination, confirmation of a diagnosis is tough but it can be contact dermatitis, rash due to friction rub, folliculitis, cysts ,molluscum contagiosum(multiple, small, dome-shaped papules, often with a central depression or plug) or genital warts(caused by HPV infection).
Apply warm compresses, Neosporin ointment and calamine lotion and avoid messing with it. You can take anti-inflammatory pain killers like ibuprofen or acetaminophen. If the lumps persist then it will be best to get it evaluated from a dermatologist
Hope it helps. Take care and please do keep me posted on how you are doing. Kind regards.
Did he test the "pimples" for HSV (the herpes virus). Seems that would be a prime suspect given the location and timing of the pimples.