I have a lot of experience with absences/absent seizures. My ex boyfriend who I lived with for 3 years is epileptic, suffering from both absences and full tonic clonic seizures.
Although you would expect to see some kind of abnormal EEG result in an absent seizure patient, I think it could still show clear. As it can be quite hard to run an EEG when you feel one coming on or have one, I think they can ask you to breath deeply and quickly i.e hyperventilate to bring one on.
I'm not a neurologist but I would wonder whether these episodes were more epileptic in nature given the breathing cessation. Having said that, migraine can produce weird and wonderful symptoms. Look at the work of Oliver Saks. Moreover though, I urge you to look at some of Dr Nicholas Silver's presentations which you will find on this forum. He says that migraine can affect the autonomic system. ( Everyday examples include breathing, swallowing, and sexual arousal, and in some cases functions such as heart rate.) So although perhaps rare, it seems that migraine could indeed be the factor for you with the breathing.
Have you sought a 1st and 2nd opinion of a neurologist?