Welcome to the forum. I'll try to help. The bottom line is that your symptoms are definitely not due to herpes or any other STD, and probably are unrelated to your sexual exposure 3.5 months ago.
Herpes lesions -- i.e., obvious blisters, sores, etc -- can burn, tingle, or itch. However, such symptoms without lesions are rarely if ever due to herpes. Herpes outbreaks can be preceded by a neurological prodrome, which can burn, tingle, etc -- but prodrome is a feature only of recurrent herpes outbreaks, not the first one; and herpes prodrome typically lasts only 1-2 days before overt lesions appear.
Second, herpes outbreaks rarely involve the locations you mention, especially the first episode. For infection to take, HSV has to be massaged into the tissues, and therefore initial outbreaks predominate at the sites of maximum friction during sex: the penis in men, vaginal opening and labia in women, or the anus if there was anal sex. I have never seen a case of genital herpes that simultaneously caused symptoms at all the locations you mention.
Third, your blood test result at 3 months is highly reliable. That usually is plenty of time for detectable antibodies to develop.
As for "random stuff on the internet", it is true that there is a lot of misinformation about herpes. But you won't find it so confusing, and will find most of the information consistent with this forum, if you limit your searching to scientific sites and those run by responsible agencies (e.g., health departments, universities, etc) and avoid those run by and for people with genital herpes. MedHelp's herpes community forum is an exception; you'll find excellent advice there. Also, I can strongly recommend the American Social Health Association (www.ashastd.org), which I serve as a member of the Board of Directors.
As for "what this could be", all I can say with confidence is that it isn't herpes or any other STD. Such symptoms often have a psychological origin, i.e. anxiety-related -- but you are in a better position than I am to judge that possibility in your own case.
In any case, don't worry about herpes or any other infection from the sexual encounter described here.
I hope this has been helpful. Best wishes-- HHH, MD
As already discussed, there is no chance this is herpes and no furhter testing for HIV is necessary nor recommended. If you remain concerned about your symptoms, see a doctor or clinic. But please put herpes and all STDs out of your mind. For sure these symptoms are not due to any infection from the sexual encounter you are concerned about. If they are related to that event, it is because of the psychological connection I speculated about in my initial reply -- i.e. anxiety over the encounter magnifying sensations that you otherwise would have ignored or not noticed.
That's as far as my advice can go, so I won't have any further comments. Good luck.
Hey, thanks for the thorough answer there. I really appreciate it. This phenomenon did go away after about a week but came back again in the form of kind of burning and cramping in my inner thighs kind of slowly moving upward. Theres still no visible signs of something like herpes and this episode I think has gone away after a day and a half. I might have felt a little sick as well but that could have been due to feeling anxious about it. I kind of freaked out when I got it again because herpes is supposed to be recurrent and i've heard of some people testing positive with these symptoms. So, do I need another test to confirm? I just don't know what's going on here. Thanks again.