What could cause persistent pain and swelling in the scaphoid bone?

Hello,

A week ago I fell and hurt my wrist. After the fall, I had a bit of pain, but I have not suspected anything major. However, the day after, my hand was swollen, warm, red, and painful. I went to the doctor, and an X-ray was done. The X-ray showed no fracture, but since I had pain in the scaphoid bone, the doctor told me to have a cast as a precaution. Yesterday I had another appointment, and another doctor saw the X-ray and said no fractures could be seen. However, when he removed my cast, my hand was still swollen and painful, especially when he pressed on the scaphoid. So, I am in a cast again for another three weeks, and after, I have another appointment, where I will do an X-ray and CT scan if still in pain. I explained to the doctor that I was having pain in my thumb apart from the scaphoid area, and he said it was everything from the scaphoid, but still, my diagnosis is unknown because no fractures can be seen. Still, I am experiencing pain in the scaphoid area. If not a fracture, what might it be?

Kindly advise.