Mine was definetly uncomfortable but did not hurt nearly as bad as the procedure they typically do before that one -can't remember what it's called -starts with an E. Also, because the first procedure was so painful and no one warned me to take advil, I loaded up on it for the HSG and that helped immensely. I know it's not recommended but done once will not hurt anything -I took 4 advil/Ib profren about 3 hours before the procecure and another 2 more an additional advils .5 hour before the procedure.
Good news is we conceived the month following the procedure -after 1-year of trying

Good Luck!!!!!