Endometrial biopsy

I have to have an endometrial biopsy next week and after reading many posts from women who've had it, I've worked myself up to an even higher level of apprehension than I had before.  Some women stated that it wasn't that bad while the majority said it was very painful, although quick.  I've been trying to get myself psyched up for this test.  I thought about the worst pain I've experienced (I've never given birth) and charley horses came to mind.  I get them in the middle of the night in my calf muscle and they're agonizing...and last quite a few minutes sometimes.  So I told myself that even if the pain of the biopsy is as bad as a charley horse, it won't last as long.  Anyone who's ever had a charley horse and an endometrial biopsy....is the pain similar?  No...I'm not obsessing :-).