Can Genital Herpes Go 3 years undetected?

It sure can. It can go much longer than that. It is estimated that 80-90% of those with gentital herpes do not even know it, because either they have no symptoms or their symptoms are so mild they assume it is something else. When you remember that 1/4 people have it, that is a lot of people who have no clue they are spreading the virus.

70% of those who contract herpes do so when their partner has no symptoms at all. This is why it is so important to actually have a blood test done to find out if you or your partner actually has it. You cannot base your or your partner's status on symptoms alone!yes
Yes, just like any other STD. People can be asymptomatic for a very long time. Herpes is in the same family as chicken pox. One of the unique qailities of the virus is that it hides in your spine. You may have chicken pox once as a child then it goes into hiding for several years or even for the rest of your life. Sometimes the virus travels back to the surface and reveals itself as shingles. It is a very complex virus and the only ones with these qualities.