Suppressive (daily) antiviral medication only reduces the risk of transmission by about half (50% or so). We can still pass on the virus, even without symptoms - a phenomenon called "asymptomatic shedding" - we can be contagious at any time. Adding a condom/barrier with every sexual contact reduces the risk further, to negligible levels. However, the risk, even with these steps, is still never zero. Therefore it's important to take two additional steps: abstain from sex during any symptoms, including prodrome (signals that the virus is active, which can include itching, tingling, burning, nerve pain, flu- and cold-like symptoms, and in some cases, headache and nausea); and most importantly, disclose before every sexual contact. I cannot stress this last directive enough.
How were you diagnosed with HSV2?