Ally,
My daughter is the same age as your little one (She was a FET after 6 months) but previous to that I had a Stim fell pregnant carried for 17 weeks then had 9 transfers to get a positive so all up it would of taken about 16 months in the freezer.
As I was paying another FET storage fee I asked the receptionist if we get warning to when it is going to expire and she said it was 5 yrs and then send you a letter...not that I will be waiting quiet that long
Bec