It really just depends on a lot of factors.
Most men start having moving sperm within the first year (often within the first 3 months of the reversal).
Pregnancy rates are really conflicting, though, ranging from 30-75% of men being able to conceive again, so you may not even be able to, especially if you both are on the older side at this point. Remember that a lot of factors have to line up in the first place, not including the reversal, so it was unlikely to happen the first few tries anyway.
You may want to talk to your doctors and both of you get tested for fertility at this point.