What causes Ponyboy to be worried that he might not have asked for Darry while he was ill?

Ponyboy realizes that Darry might not recognize his love for him. When Jerry told Pony that his brothers were there, Pony ran for the door to meet them. He landed in Soda's arms. Soda put him down and asked what happened to his hair. Then Ponyboy saw Darry. Darry leaned in the doorway, he was the same Darry. Pony was horrified to realize that Darry was crying. Suddenly Ponyboy knew what the others had said was true. Darry did care about him. Pony ran and latched on to Darry and told him he was sorry. Ponyboy was finally home.