Hello and welcome to HCM.
Thank you for your query.
From the description provided by you, the possibilities in order of their likelihood are:
As the most likely diagnosis is herpes, let me list some of the most common symptoms for your reference, they are:
-Swollen lymph nodes
in the groin region
These symptoms are seen initially during the infection. Once the infection progresses, we can see ulcers, blisters or sores around the genitals. In females, the sores are usually inside the vagina and at times ulcers or blisters are seen around the anus.
In some individuals, when there is no outbreak of herpes taking place, the infection can be less contagious, and possible not transmittable. This could be one reason why your partner does not have the infection.
I would thus request you to visit a doctor at the earliest, get diagnosed and accordingly treated. It would be wise to refrain from all sexual activity in the meantime, and also request your partner to get screened again.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you.