Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to obtain a history from you and examine you, I can not comment on a formal diagnosis or treatment plan for your symptoms. However, I will try to provide you with some information regarding this matter.
You can get the aura of a migraine without a headache. This is termed acephalgic migraine. It most often occurs in people with a past history of migraines with aura but can occur “out of the blue”. If you have a history of prior visual disturbances with a headache (i.e., migraine with aura), then it is likely the same without the headache. Also, if it includes both eyes and moves slowly, it is more reassuring to be a form of a migraine. However, if you have never had an aura before, you should be evaluated for possible ischemia. This would include neuroimaging (typically an MRI of the brain) and other evaluations looking at the vessels and heart.
I suggest you follow up with your primary care physician to discuss.
Thank you for using the forum, I hope you find this information useful, good luck.