There is never a "good time" to do anything in the Air Force today in regards to getting married, having kids, etc... So if you plan your life plans around the Air Force's time line, then you will never accomplish anything in regards to your home life.
I got engaged and we lived apart for 3 years while I went through UPT, IFF and the RTU b/c she couldn't move due to her job. I got married immediately after the RTU and then went TDY for 1 month exactly 2 days later then got to my new duty station and within 1 month was deployed for 4 months. Another example is that my wife was pregnant and I was TDY for 5 months of the 9 months of the pregnancy.
So, just do what you want, when you want to do it and don't think about the Air Force...