I had a sexual encounter around two months ago where no oral or penetration/intercourse occurred. There was skin to skin and genital to genital contact but mostly only mutual masturbation. I understand this is considered low (or even no risk) but since that encounter I've been experiencing a mild burning and overall general soreness of my glans/urethra which has persisted for weeks. Ejaculation burns and sometimes there's burning when urinating.
I was given tests for chlamydia, gonorrhea, syphilis and HIV which all returned negative. I have been scrutinizing my genitals for any lesions, sores, warts etc during this time but have not found anything suspicious to indicate herpes. I have noticed a lot of redness to my glans which looked almost like eczema or balanitis but it seems to clear some days and appear worse at other times.
My question is, does this sound like an STD? I have already taken all the STD tests they offer at my clinic so I'm not sure what to do next. This problem only started after a sexual encounter so it makes me think it must be related.
I appreciate any replies and advise. Thanks!