We recommend having the IUD taken out after you immerse because the bleeding that accompanies the removal is considered dam makkah and does not render you niddah. Bleeding more than two days after removal cannot automatically be considered dam makkah, but probably will not render you niddah if you take the usual precautions associated with staining (colored underwear, etc.).
We generally recommend abstaining from intercourse while bleeding/staining until the bleeding subsides, even though you are not niddah. If you follow this recommendation you are not behaving in a manner at odds with your husband's custom.
If you have the IUD taken out while you are niddah, it may interfere with completing the clean days in a timely manner because you need to have an acceptable hefsek taharah, day 1 bedikah and day 7 bedikah. If you have the IUD removed before you start the clean days you would essentially have to wait until the bleeding subsides before performing a hefsek taharah. If you have it removed during the clean days, the subsequent bleeding may prevent you from getting an acceptable bedikah on the 7th day.
Ultimately it is your choice and you can decide when in your cycle you want to have it removed. There are no other dangers or halachic implications involved.
Please feel free to get back to us with any further questions.
B'Hatzlacha!