Third IUI and it was very different

So, I guess I don't know what I am supposed to expect. With the first two cycles, I had bleeding immediately following the removal of the catheter. There was blood on the catheter and on the table when I was done. The NP who did those seemed a little confused when it happened, but stated it was probably normal because spotting and cramping were normal. I never had spotting following and obviously neither worked because I had my third IUI yesterday. Yesterday, the nurse did my IUI and it was completely different. Zero pain, zero blood. I'm so confused.