Can you add other emojis to those found in the emoji keyboad for iOS 9.2

I like to add emojis to brighten up my calendar and such. While the emoji keyboard on iOS 9.2 has a lot of emojis, I cannot find some such as the Rod of Asclepius for medical appointments, a picture of a tooth for dental appointments, or a bag of groceries for grocery shopping. I'm not against buying an app for resolving this sort of thing, but the couple that I have wasted time and money on have been thoroughgoingly useless.