"First, realize that you're not alone. Around 70 percent of women who can orgasm in other ways have difficulty reaching orgasm during penetrative sex. Physically, a woman needs the right type of stimulation of her clitoral region to reach full orgasm. It can also be a mental thing, though, where a woman simply finds it hard to "let go" during full penetrative sex. And, of course, it can be a combination of both."
Read more here .