Blacking out while shaving?

I had something really weird happen last night while I was shaving under my arms. For whatever reason, I don't usually look down at what I'm doing and sort of just feel my way around but I was like "huh why do I not look at what I'm doing?" And so I tried but then immediately had what felt like pre-syncope but even worse than usual? I was sitting on the side of the tub, so not usually a position that I get pre-syncope in. Once I lifted my head up it sort of went away and I thought it was a fluke so I tried again and it happened again immediately. Does anyone else have that, too? It was definitely worse on the right side, if that makes any difference.