I do not think you are pregnant, as 5 of the tests have turned out to be negative.
Your problem seems more like an intracranial problem. You would benefit by getting a plain CT or MRI
of the brain done.
Make sure that there is no intra-cranial space occupying lesions or anything as such. If the Brain imaging is normal, then we need to possibly look at other causes like Migraine
Please go ahead accordingly.
I wish you quick recovery.