(Hatafat dam brit is the "drop of blood" drawn from an already-circumcised male as part of his conversion. It is the "completion" of brit milah, if you look at it as completing the original circumcision.)
This is a question that gets bantered around a lot, but no one gives an answer. I asked around and got a few answers, and maybe you want to share your knowledge/experiences in the comments! For those of you who are new to the blog, I'm female. I have no personal knowledge of this issue whatsoever.
The answers all boil down to "Not really." And usually, the anticipation was the worst part. Just like any other time you get blood drawn!
Interestingly, it was mostly described as "uncomfortable." Why? Think of getting blood drawn from a finger stick: sometimes the blood doesn't immediately come out. What do they do next? Squeeze your finger.
The other interesting answer shared that there may be two pinpricks because apparently there is an argument about where the drop of blood should come from. Therefore, don't faint if they say you have to get "stabbed" twice!
In summary, it gets built up as much scarier than it really is. If anything, it's uncomfortable and somewhat embarrassing. It's certainly not anything to be afraid of. You can feel better by feeling sorry for those poor converting schmucks who have to get a full bris!