Either way, with a 9-week negative, the chances you were infected are still close to zero, but as I mentioned before, do follow up at 12 weeks post exposure,.
This is what I can say with confidence for this exposure, but, as we are not doctors here, for the future you must follow his doctors instructions to ensure his own well-being and yours.
I would also like to say that I'm really sorry about your husband's situation, but please try to stay strong and fight. HIV is a manageable diseases and he can still have a long, full and hopefully happy life.
His not on meds during that time it was just last dec he just new he was positive just this january
A 9 week negative has never been seen to turn positive later, but you're doing the right thing to test again at 12 weeks. Most test kits are reliable, but having the tests done at a clinic would preferable ((in the future)).
If your husband is on meds, then it would be almost impossible to get infected.