Hi Amber,
You and your husband both have normal Hb and MCV, so either your child is not thal minor or he is a silent trait carrier, which would mean one of the parents is also a silent trait carrier. I think it is more likely that the low MCV was caused by something else like iron deficient anemia or the illness and is not any cause to worry. I would suggest having him tested again at around 9 months to see if his MCV has risen.
If your son is a thal minor, please don't worry. Most minors have no problems and since both parents have normal hemoglobin levels, you can expect your child to be the same as the parents. His only real concern if he is a minor would come later in life when he decides to be a parent. If he is a minor, his partner should also be checked for thal carrier state to make sure there is no chance of producing a thal major.
Please let us know what further testing reveals. I will be surprised if thalassemia is involved.