This might be a question you want to pass by your doctor. I can tell you what I know but I don't know the medical impact of Kilz on a pregnancy. (Bear with me ...)
First, there are 2 types of Kilz. Oil-based and water based. The oil-based Kilz is noxious and will give you headaches, and make you sick if it's not adequately ventilated to the outside. After a while, it does disapate. HOWEVER, beings that you're pregnant, there may be risks of inhaling it to the baby since it can make you sick. If it can make you throw up, well, you can imagine what it might else do.
As for the mold being sealed behind the Kilz, that should be OK. As long as it doesn't come back and the maintenance mand did put a top-coat on it when it dried. From there, you just live a normal life I suspect. My $.02 on the 'bigger picture'. Whenever there are chemicals or noxious fumes around, get out of the house until the work is done AND the smell is gone, pregnant or not. Some folks are sentative to water-based 'anything' let alone oil-based products, so that's the general rule I'd follow. I'm sure your baby is more sensative to 'stuff' than you are.
If I was your Dr., which I'm not, but if I were, I'd say you should err on the side of caution. Really, it protects him from a lawsuit AND your baby's health. It's just the prudent thing to do. My best to ya and hope this helps.