Ever since Game of Thrones has shown 4 dragons in the intro, the internet is losing its mind, especially after the
death of one dragon
in last episode.
One fan theory says that Drogon is actually a female which layed multiple eggs when she disappeared in the season 5.
Another fan theory which is very famous says that Daenerys herself can transform into a dragon to become real mother of dragon.
I am interested to know what books say about it. In books, how many dragons are there in present day (not talking about legends)?