Infertility Announcement (non-family)

My DH and I have been married 17 mos and TTC for 14 mos. Our fertility specialist says we'll do 1-2 more rounds of IUI and then that's all he can do. We're not considering IVF.
I'm 36 and my DH is 41. My friends and coworkers keep asking when we're going to have kids since we're not getting any younger. Any advice on what we should say without them knowing about our personal struggles to conceive?