Lea - something else to keep in mind - i had an IUI (as i believe you did too) - i ended up conceiving up to four days after the IUI itself this cycle - so it's possible your pains are lingering o pains. and having had an IUI, you'll find that your body has been forced to open and accept "foreign" matter when you were catheterised for the procedure - i found after every transfer (we had 8 in total with the IVF transfers) i would find my cervix and uterus would be a bit "niggly" for a few days cos it didn't like it...