Certainly there's no reason to feelstupid! Some of the things I've learned about rabbits overthe years has been because I've made mistakes. Experience isa good teacher
Sexual maturity can be as early as 12 weeks, although litters producedat this age are not always viable. Sometimes when a doe isbred to a very young buck (or if she is very young herself), she abortsthe litter by 14 days into her gestation. Gestation averages31 days, so you'll need to figure out when the buck and doe have beentogether (counting 31 days from the last day together would be about aslate as the litter could be born). Keep in mind that doeswill mate again *immediately* after giving birth, so the doe shouldnever be left with the buck.
There are times when does retain the kits, which may mummify or beginto break down and rot. Being able to palpate (feel for babiesin the abdomen) is a very helpful skill in determining whether or not adoe is pregnant. Avet whos very experienced withpalpating rabbits can also determine pregnancy after 14 days,however, not all vets have this skill, nor are they familiar withreading sonograms from rabbits.
If you can provide more details, I might be able to provide you with more info.
Pam
