It is definitely painless - very similar, or even easier, than a pap test.
They should show you your partners sample (with his name on it) and once the procedure is over just relax for the day if you can.
The HCG shot may make you feel bloated and crampy. (I found that was the worst part of IUI). Drink lots of Gatorade if you can (1 litre a day). The salts and hydration help minimize the bloating.
Good luck!! I have done one round of IUI and waiting to start my second round.
Stacey
IUI is painless, kind of like your annual exam. It's very quick but you will probably be asked to lay down for 10-15 minutes. You can test before your beta but you can get a false positive because of the trigger. So, if you do get an early positive HPT you will have to test the next day to make sure the line is not going away.
Good luck!!!!