Unsure, could use some guidance

So I have an MRI and EEG scheduled for next week but I have this feeling that what ever has been happening to me isn't seizures. I work at a big healthcare facility so I see my doctor every day and we're close...I feel she ordered all these tests just to cover all her bases and because I'm closer to her than her average patient...she even did say herself it didn't sound seIzure like. I've had 3 different situations all within a year. The first two happened after me standing up and walking somewhere fast. Suddenly my vision started to go out (from my eyes fluttering open and closed and not being able to keep them open) my head got this really weird warm/ lots of pressure feeling and I shook (not violently) the whole time I was still very aware what was happening, I could still hear the tv and I was thinking in my head when is this going to stop what is happening. The first two times happened standing up and I was able to keep my balance and stay standing. Fast forward a year and I had the exact same situation happen, standing up fastly, same sensations, still aware, except this time I lost my balance and fell to the floor because the shaking was a little more violent than past times.. I finally made an appointment and my doctor has ordered an MRI and eeg like I mentioned earlier. Obviously these procedures cost a lot of money and I'm concerned because a lot of the seIzure experiences I read about don't sound too similar...I find it weird that the episodes always happen after standing up as well...my blood pressure is completely normal though. Has anyone experienced anything similar. Would you guys recommend going through with the tests? Thanks for any advice!