You should not experience any complications. Once the discectomy was complete, the poblem was fixed.
That is a minor surgery when compared to most back surgeries and since it is not too invasive, the spine and muscle structre are not too impacted.
I am not a doctor but I would think that you should be fine and you and your hubby will have a great time with the second baby.
Always check with your doc when you are concerned about something like this but from a laymans view, I would be too excited about the 2nd baby and probably would be blinded to the pain until it was too late. :>)