Hi heather and welcome to the board!!!
I have a Mirena IUD (IUD with low dose hormone) and mine is coming out in 9 days. You are immediately fertile on removal of an IUD as it is a barrier method of contraception. As soon as the IUD is gone pregnancy can happen at the next ovulation, you don't have to wait for your cycles to settle as with hormonal birth control.
If you have a low dose hormone IUD like mine, then you commonly ovulate within days of its removal due to the change in hormone status. Some women don't ovulate for several weeks though.
The official line is that your fertility should return immediately
Claire xxx