sperm can't live that long, so it should'nt be any problem, even if you were ovulating when they remove it the sperm will be dead by then any time after that though you can become pregnant, so if you don't want to be be careful and if you do have fun!
Last wednesday? Meaning you still had the IUD in place at the time? Then none. If you have the IUD in place then your chances of becoming pregnant are slim. Now if you meant to say when you take the IUD out...then you can conceive anytime, depending on how soon you will ovulate.
When I had mine removed last June my doctor told me it was a possiblity that I could get pregnant of I had sex before the removal. I'm sure they will go over that with you.