My boyfriend and I have been sexually active for a number of months now, and I have never had an orgasm. Lately however when he is stimulating my clitoris it gets to this point where it feels really good but I really want it to stop, I just can't handle the feeling. Without meaning to I often find myself shifting slightly so that the feeling isn't so intense, but I want to know, is that me approaching orgasm?

How old are the two of you?

I am 21 and he is 25.

I am 21 and he is 25.

Scientifically orgasm is the feeling of relaxation after masturbation.
Clitoris is a very sensitive part of a female's body it contains a lot of sensing cell which give you this pleasurable feeling.
Yes its approaching you to orgasm !

But I find the feeling very hard to take, and can't stop myself from shifting. How can I push through and finally climax?

Slowly as you indulge in the activity the sensation increases and reach up to a certain optimum level
At that time you are near to orgasm

It varies from women to women and depends upon your resistance