best way to do it. Layers and layers of flooring don't work well.
Yes, there is a chance that some of the old flooring or mastic contained asbestos. If the flooring came off in big pieces then you have limited your exposure somewhat. Wiping down the surfaces with a wet cloth was a good idea.
Now, whether or not you inhaled asbestos is sort of a moot point. What's done is done. For your comfort, the baby won't be affected. Asbestos is airborne and can't harm the baby in the womb.
I would wipe down the rooms again with a wet rag to collect any left-over particles. Be sure to catch the top of the cabinets and any other odd hiding spots. Even if it was asbestos it certainly won't kill you soon. It may not have anything to do with your eventual death. The stuff isn't good, but it isn't certain death either.
Your father inlaw seems a bit daft to just go ahead and ignore the dangers, but that's his choice I guess.