In your case, you and your husband could both have it without symptoms or there's a small chance it could be a false positive (4% according to IGenex versus 28% false negatives).
I actually find the opposite to be mostly the case compared to what you experienced. Many people on here have many symptoms yet test negative. I see this all the time.
A woman I sent to my LLMD just got her results yesterday and posted them on a different forum that she didn't have any double-starred bands positive on the IgM and she's pretty sick with tons of symptoms.