Is This a Sign of SP?

Ok guys, sorry in advance for yet another thread to do with SP, but I just need to ask.

When I attempt a WBTB I usually stay up for about 10mins tops maybe shorter beause I've tried longer and it just results in me laying there for a couple of hours.

Now to the question. I'm wondering if this is a sign of SP. Ok, so I am just laying there and out of nowhere it feels like my head is off balance or something. I don't know how to explain it, however I would say it feels like when you are hanging upside down for about 3 seconds and then you quickly move to an upright position. OHHH, it feels like head rush, that's it. Would this be a sign of SP because right after that I pretty much nothing happend because Ill become aware of it and it goes away instantaneously.

Thanks, FireDevil