Beginning of sleep paralysis?

Ok so I been trying to wild lucid dream for a while now and yesterday night I tryed a new technique and I stood still for a bout 20 minutes and then I feel my legs go numb and the blood stop circulating through my legs and my heart started beating fast and It was hard to stay still so is that the beginning of sleep paralysis? Also what happens after the numbness and how long does it take to reach the next point after the numbness and heartbeating?

The heart beating fast happens to me, a wave of heaviness spreads over me, and I become more comfortable than before. So yes I think it is.

Tip: I used to be freaked out about my heart beating really loud when entering SP but just breathe deeper and it will disappear.