Backing up some other thoughts - most often when a girl is off sex, it has nothing to do with your dick. It's usually something that she's going through independent of you, or something about your relationship with her.

I think that it's sometimes hard for guys to get that the desire for sex, or lack thereof, isn't necessarily about how it feels for women. I mean, that can certainly affect sex drive. But frequently we aren't in the mood because we're stressed, tired, worried, or feel something in the relationship is off. Similarly, frequently we're horny as anything because we're feeling secure, relaxed, happy, and well loved.

Don't worry about your dick. The only time penis size has ever put me off was when it was too LARGE, and even then there's a wide range of wonderful size. Take the time to examine your relationship with her and her emotional state instead.

got my cam workin so heres a better pic :p

The average male is between 5-7 inches. So says the medical folk.

If it's been three times in nearly four months, and it's not medical, then check around her mind a bit. Watch out what you find, though.


ManOMan

Through "extensive research",(lol) I've found that sometimes women just aren't in the mood..Not a big deal,as it's been said in here that once the drive cums back..Happy Days Are Here Again!!.If she is complaining though,then maybe look at the approach..A nice dinner out alone together does wonders..In the past,and I'll be really honest about this,I was just moving too fast,and she wasn't getting what she needed,so I needed to slow down,learn to use massage oils,and things like that to enhance the mood for her,too..Actually found out that doing things like that,made it more pleasureable for me,too.
A womans g-spot is about 1 1/2 inches in,so unless your smaller than that,you shouldn't worry..Making it love making session instead of a fuck,made a difference..Can't keep that puppy in there for an hour and a half,but you can make HER cum that long with the right research,lol..
Be more secure in yourself too..If you know that you did all you could to make it better for you both,then,it's time to talk about it,and see where things can be done differently..

Dude, I'm just a little over 7.5inches, and I have had girlfriends where certain positions were painful. If you get in there and happen to poke her cervix.....let's just say it isn't pleasant.