It seems the history that you are having headaches
associated with aura. This is because of migraine
as suspected by you. The migraine headaches are known to increase in frequency during pregnancy
and decrease after delivery.
However it requires treatment by the use of drugs to prevent migraine attacks.
The commonly used drugs are flunarizine
or beta blockers, since you will be breast feeding the baby the drugs need to be used carefully, hence I advice you to consult your doctor for examination and treatment accordingly.