I have a sentence that says, "She has had repeated bladder infections, an appendectomty, 3 dilation and curettage's, a tonsillectomy, and a history of yellow jaundice as a child." - Now my question is, Is that the correct way to write out 3 dilation and curettage's? If not what is the correct way to write that? To me it just doesn't look right.

Can any one tell me if ABG should be spelled out as Arterial blood gas

It would depend on where it is being used. You can not use abbreviations in admission diagnosis, discharge diagnosis, preoperative diagnosis, postoperative diagnosis, impression, assessment or operation performed.
Hope this helps.