A biopsy is sort of like a bad (not really bad) pap smear - if those bother you a lot, then this might hurt a lot. The biopsy itself feels sort of pointy, but it's very quick - it only hurts afterwards if your uterus decides to cramp. Which mine did, and I was kind of sore for about an hour or two afterwards. I just had one (which turned out to be three, which probably made things worse) a few weeks ago.

It's one of those things where, if you can manage to relax, it will help a whole lot. I don't know if you can take tylenol/advil/something beforehand; I didn't ask and I didn't really need to, and I have a fairly low pain threshold.It's not exactly loads of fun, but you'll be fine.