Congratulations! It is rare to see a plug ... they are often eaten and/or lost in the bedding. The plug means they have done the "deed" and the odds are in your favor for a kit/kits ...
as long as they are both fertile. He could be shooting blanks into a dry well.
CAUTION: Do NOT palpitate or "poke around" the tummy area at any time, this could kill any kits she may be carrying. Minimum handling by family members friends.
When walking around with her hold her gently, but firmly next to your body ... you don't want her to jump out and possibly hurt any kit/kits she may be carrying or hurt herself.
A weighing scale that weighs in 1 or 2 gram increments is needed to chart her weight and that of her kit/kits, once they are born. Chinchillas need to be weighed in grams rather then ounces/pounds because of their size and the importance to their health of any gain or loss of weight ... loss of 5 to 10 grams in a kit can be a warning of something that is going on that needs your attention. Rarely does a scale that weighs in ounces display the ounces in small enough increments to give you an accurate reading needed with chinchilla kits. Healthy new born kits have a birth weigh of 33+ grams. A kit that is unhealthy/very small and not likely to make it has a birth weight or 30 grams or less. Both kits would weigh in as one ounce. A loss of 5 grams would be a big red flag in this situation, but 5 grams would rarely be noticed by the eye or or by a scale weighing in pounds and ounces.
1 ounce = 28.35 grams
1 pound = 473.18 grams
How old are Lola and Carlos?
What type of a cage are they in at this time? What is the size of the delivery/whelping cage? Number of levels in the cage they are in now? Size of wire on the cage?
Do you have a separate cage to keep Carlos in once it is close to time for Lola to deliver?
Do you have separate cages for when the kits need to leave the parents at 6 or 7 weeks of age?
It's time to start planning ... time passes much faster than you may think and you probably have less than 100 days to be ready.
Most births go off without a hitch ... if preparations are made for the safety of the kits once they are born, you would not want to loose a kit, if you could have saved it, had you been properly repaired.