Originally Posted by DoulaLC
The lightheadedness could be from a number of things besides possible pregnancy. It would be unlikely you would be feeling pregnancy symptoms just yet as implantation often takes several days to be complete. Many women do feel differently early on however.
If you happened to ovulate very early in your cycle, which is possible....and the IUD didn't do the job....which is possible....you might get an accurate result on a test in several more days. However, the odds are slim that you are pregnant simply because those two situations greatly decrease the probability of pregnancy occurring.
See how you feel in another week....try a test at that time if you still feel it might be due to pregnancy. Keep in mind, the urine tests become more accurate the closer to a period you get.