I too have started to wonder this... I've now been with three women in my life...
The first was high school sweetheart and I was never sure she climaxed, she'd just get really sensitive, everywhere, and I'd have to stop touching her. But it was nothing like what I know orgasm to be.
My second was my now ex wife, I definitely knew when she came because her body would shudder, toes would curl and she'd go silent... it was sexy and I knew she was in heaven.
Now been dating a new woman, and it feels much like it did with my first... she just gets sensitive, but VERY wet, and lets me continue but I can tell she is done (just not sure if she got to heaven
) She says she climaxes so I will just believe her! no complaints at all, but sure would be nice to be able to recognize it.
Interestingly, my ex was very comfortable touching herself, the other two won't admit to ever doing that