Girls,

It takes five days to establish a pregnancy. Doing any kind of testing in the five days after your IUI is a waste of time and money because the pregnancy doesn't technically exist.

Here's how it goes:

Ovulation - lets call it day 1 (because we all ovulate on different days): the guys go in and hopefully fertilise the egg. At that point it is a single cell.
Day 2: Eggs divides into 2-4 cells within the nucleus
Day 3: Divides into 4-8 cells
Day 4: Divides into 8-16 cells
Day 5: has divided into more than 100 cells - it's now called a blastocyst
Day 6: hatching and looking to implant

During all this cell division the embryo has travelled down the fallopian tube to the uterus and is looking to burrow into the endometrium on day 5 to 6. You may get some spotting between days 21-28 of your cycle but not always.

So any bleeding you see on the day of IUI is usually caused by the cateter passing through the opening of the cervix. If you get anything from the speculum its more likely to be bruising.

Cheers,
OP.