My tooth is beginning to ache again.
It depends how the word is used. Most often, belly is a noun. example sentence: Our dog likes to have her belly scratched. Belly can be an adjective as in the sentence below: The child says she has a belly ache. In the sentence above, belly is an adjective describing ache.
He took an aspirin for the ache in his side.
Emily went home from school with a stomach ache. Muscles can sometimes ache if exercise is too strenuous.
The spurned boy thought that the ache in his heart would never heal - it did, eventually!
As I walked trough the doors on the first day of school I felt my Belly start to quiver and ache.
My heart aches for you.
As l hurried into the room l bumped my head on the wall, it was so great that the ache on my head would not stop
I have a stomach ache is preferred. Have got is not incorrect, exactly, but the got is unnecessary, and therefore excessive.
Once the veins have become varicose, the legs can start to ache.
My mother had a severe head ache after the fall off the ladder. ( not really)
A Classic Example
A pain that rhymes with stake would be an ache.