nosy co workers

My husband and I both work in the same hospital. We've been married for almost two years and everyone is always asking us when we are going to have kids. We've been trying for a year now, and just about every other day people are asking me when I'm going to get pregnant. Its starting to get really annoying and it stresses me out to have to put on a smile and laugh and say "hopefully soon!". My husband is super private and I don't really want to tell them that we are having a hard time (at least not just yet). How do you ladies deal with people asking constantly about when you will get pregnant?