First RE appt

Saw an RE for the first time yesterday and she said due to my PCOS (which is mild) and my DH's sperm count (which is not good) we can do one iui and then have to move on to ivf. She said our probability of conceiving with iui was like 5%. Has anyone else gotten pregnant with iui and had that low of a probability rate? I know it's possible because God gave us our son 4 years ago and I wasn't on any meds or anything. He is literally a miracle!!