Six months is a bit long for you to carry STDs. However, you could have infected your wife between then and now. And women can be infected for months, with symptoms on and off.
Your wife needs to be examined and checked for STDs, especially gonorrhea and chlamydia. This needs to happen regardless of the results of your own tests. In most men with gonorrhea or chlamydia, the infection goes away in a few weeks without treatment, so you could have infected your wife but have negative tests at this time.
Sorry, I can't sugar coat it. She needs to be checked to protect her health, and to prevent the possibility that you will be reinfected by her.
Good luck-- HHH, MD