Fantasy Literature

And that's what Dany's vision of Rhaegar telling his wife "the dragon has three heads" meant? Rhaegar believed he was the Prince that was Promised (Azor Ahai) at one point and Maester Aemon believed he was too. Then Rhaegar believed his son Aegon was the Prince that was Promised because of the comet that appeared. Aemon later believed it was Dany when he heard about her and the dragons. When Rhaegar told his wife "the dragon has three heads", he could be trying to tell her how he had to have a child with Lyanna to save the world? I know it's a stretch, but possibly the three heads are Dany, Aegon and Jon?