@Brandy: it depends.
When it comes to Infertility treatments it's all about isolating the different factors. You want to make sure you ovulate, have sperm meet egg at the right time, have the follicular tube pick it up, have the egg fertilize and stay in the tube for a little bit, have a thick enough lining in the uterus for the egg to implant and then there is also that little bit of luck involved.
In your case you have intervened twice. You know you ovulated and you know the sperm got to the egg. Now if the sperm analysis is completely healthy and you would have had TI at the same time of an IUI, there really wouldn't be much difference. IUI is the answer for minor sperm issues and timing questions.
The issue is just because you ovulated and the sperm got to the egg, it doesn't mean that all the other things happened....
That's why the recommendation for couples where nothing is obviously wrong is to do an IVF because that way they know the quality of the egg and eliminate the issue of the follicular tube picking the egg up and the egg being fertilized and hanging around the uterus at the right time....
Having said all that, it does not make sense to do many IUIs back to back with good sperm quality and tracked ovulation...because if that doesn't work sth else is wrong...and you can only find out what by doing IVF.