Your total number of Dratini candies will be an accumulation (a sum) of all your Dratini candy rewards.
The number of candies you get from an egg is random (between some limits).
So if you
- get a Dratini (which is one of 17 10km egg Pokémon: ~6% minus an unkown percentage because you can get lower level Pokémon from eggs - see comments - so I'll halve it: ~3%) and
- it will give you 3-35 Dratini candies (it should be random distributed : ~3%,)
- and if you haven't get other candies from catching
than you will have 44 Dratini Candies (at ~0.2%1%).