I am a woman and could not agree more with the above quote from christnthms. Based on my experience your size is average and 1 or 2 inches more or less don't make a difference.
I have not have sex with lots of men but I have had sex with men in various sizes and the size does not make a difference is how you use it that does. If you penetrate and can't feel the tip touching the end of the vagina when you move back and forth (at least for me, can't speak for other women) there is space to be filled before a G-spot orgasm can be felt.
Things that you can do when you are below average that will work:
- add foreplay and pay special attention to the clitoris area before you penetrate (my favorite orgasms are the ones that start with an clitoris orgasm and are followed by penetration orgasm)
- ask the woman to be on top that way she can push herself into you as much as she want while you push your body up
- if you are on top asks if she wants you to push deeper and if she says yes press her knees and thighs against her chest slowly while you push into her
- avoid doggy style as it elongates the space to be filled
If you are above average you should be careful while doing the things above (expect the foreplay) because you can hurt a woman or make her feel uncomfortable.