Hi there. This sounds like a confusing situation for you and your partner.
Here are a few facts about herpes that may be helpful.
When someone goes in for an STD test and asks their doctor to test them for "everything," they probably are not getting a test for herpes. Doctors only test for herpes if there are visible sores, or if the patient asks specifically for a blood test for herpes . Unless your partner had sores, or asked for a blood test, he probably was not tested for herpes when he went in.
Herpes can exist in the body for years before someone has symptoms. Your partner might have had it and never known. He could have gotten it from a former partner who might not have known they had it. Condoms and other barriers only reduce the risk of transmitting herpes, they don't prevent it.
Lastly, if he did get a blood test in January, he could have had it and his results might still have been negative. It can take weeks after exposure for herpes to show up in the blood in a way that doctors can test. He could have caught it from someone a while before January. False positives and false negatives can sometimes happen too.
For many people. a herpes diagnosis can be initially scary for everyone involved. It is much more common than many people think and most people who have it are able to keep it under control with anti-viral medications. For more information about herpes, try
http://www.herpes.org/smart-living-with-genital-herpes/
Also, the folks over at Planned Parenthood recommend this editorial piece:
http://thehairpin.com/2012/04/the-perks-of-herpes/
Wishing you the best of luck in this challenging time
Your friends at SFSI
RT/LT