for those who have cum from piv, do you feel the build up ?

hi, i'm new on reddit so i hope it's the correct place to ask that.

i'm a 21 years old woman, who has never orgasm from piv (like the majority of women, i know). BUT, during piv (whether it's during sex or with my toys), i feel this intense pleasure. it's really good and i feel like i'm on the verge of the orgasm, but it's not building up like with clitoral and g spot stimulation. and so in my head, the building up is what allows the orgasm.

so my question is, for those who have orgasm thanks to the a spot or deep spot (don't know if there is a difference between those 2), do you feel the orgasm build up, or is it really intense from the very start ?

again, i want to clarify that i'm not talking about the g spot, but the deep spot. thank you for your replies :)