Did you know that chinchillas are pregnant for 111 days.  Did you also know that if you find a wax plug in their cage, they have mated and that is your positive pregnancy test.  If it is not too dried out you can pretty much calculate when your chinchilla will be giving birth.  It may be 110 days or even 112 days but usually it will be 111 days exactly from the point of losing the plug. 

If your chinchilla gives birth, give her a bit (2-3 ml) of orange juice after the kits have been born.  This must be 100% juice.  It can be a combo juice such as orange/pineapple/banana, orange/peach/mango etc.  If she seems a bit slow or tired after birth, give her a mixture of  equal amounts of oats, wheat germ, dry baby cereal and dry powdered lowfat or nonfat milk.  This should only be sprinkled over regular food in amounts never exeeding 1 teaspoon daily.  This is a good supplement for underweight chinchillas and expectant mothers for no more than two weeks prior to giving birth.  If you are unsure of her expectant date, just give her this mixture as a treat up to three times per week.