BEEN ASKED, 100000 TIMES!!!!!

I know this has been asked 100000 times, but I need some help! I finally have got to the point where I can get self-sustained contractions. They get pretty hard too! They finally happened when I was on my stomach. They were hitting me so hard that I was raising my ass off the bed, thrusting my hips and shaking. I flipped over and got on my side and they were able to continue. Still, no erection but lots of pre-cum. But that's about it.

My question: is this what I am supposed to feel and simply let it continue until the big BAM? I guess I need more patience. I imagine this feeling should continue until it takes me over the edge. Just want some advice. Thanks.