2 IUIs contemplating IVF

My husband and I have been TTC for almost 2 years. We have never had a positive test and as far as I know I've never been pregnant. We have been diagnosed with unexplained infertility. All our tests have come back normal. Yet we still aren't pregnant. I am trying to decide if I should skip the 3rd IUI and just go straight to IVF. For any ladies who have gone through IVF what is the process? How long does it take? Any and all opinions are welcome. Someone please tell me I'm not alone,