I think that if you're used to, for yrs, having a clitoral orgasm we've conditioned ourselves to this feeling. It builds up, explodes & then cools off. So we know that amusement park ride.
If we experience other types of orgasms they can feel like a brand new ride. We don't know what to expect or what just happened & have nothing to compare it to. So I think what you're feeling makes sense.
I remember saying after a certain different type of orgasm I never had before, "what the hell what that?" Only we can answer that. If it repeats, for me, that it happens several different times then I figure it's a orgasm I'm not used to, but for me it is a different type. Some cause me to explode & that's it. Others when they start, I know will lead to more.
And the good ole key of relaxing & just enjoying the ride is paramount. I'm not keeping score