What to look for. You should first consider that not everyone has herpes signs or symptoms, or they do not notice the symptoms, or maybe they just have not had symptoms yet. This is important to realize because the lack of symptoms does not mean that you or your partner does not have oral or genital herpes. However, if you are concerned you or your partner might be having symptoms or a herpes outbreak, it is important to know what to look for. Your common, most characteristic sign of herpes is going to be a blister or a cluster of small sized blisters. The blisters may be filled with a clear fluid. And since herpes is usually found on the mouth or in the genital region, if you have a clear blister in one of these areas this may be enough reason for concern. In these cases, most people will seek a physical exam by a medical professional. If you have a full blister they can perform a herpes culture which is a swab of the blister. This test can actually test you what is causing the bump. Sometimes herpes does not turn in to a full blister, it may look like just a pimple, or a red tender spot, or just may appear to be like a stretch in the skin. It is important to realize that simply because you have had a pimple or tender spot, this does not mean you have herpes. If you are worried, you can consider a herpes blood test.
Other herpes characteristics. Some other signs to consider would this area where your bump is itch or tingle? Herpes has a pretty distinct and isolated itch, usually right at the surface of the skin. More painful outbreaks may also have and aching, throbbing type of pain. Another clue is when whatever you are experiencing seems to be repeating, in the same area.
History and clinical profile: There are not that many many reasons for you to get an unexplained bump orally in the genital region. This is where the staying calm comes in. Think about it, do you have any reasonably reason to have a blister there? Were you more physically active than normal? Did you cause extra friction in that area? Maybe your clothing was a little too tight the day before? Do you have any reason to suspect it is herpes? Did a past partner have herpes? When was the last time you were tested? Also, for the ladies, please consider, a large percentage of your genital region is not visible to you so there before you may not know you are having outbreaks. If you are having what you think are unexplained and recording yeast infections you might consider a quick herpes blood test.
In summary, if you are worried and having a blister, you might consider a physical exam and / or culture. You may consider a herpes blood test if you do not currently have a full blister, have another symptom or other reason to be concerned about herpes, or if it has simply been since since your last herpes test.