Dealing with family when TTC

A
Hello,
I have been TTC for only a few months but I'm finding myself getting really irritated and sad when someone says "so when are you guys going to have kids?" I know people are innocent and do not mean harm, but it hurts! It gets worse with each unsuccessful month 
:( what do you guys say to relatives who ask?  I usually say "one day" but one of thes days and I'm gonna snap!