Prolonged bleeding on femera

So this is the start of my 3rd letrozole cycle. Last cycle I took 7.5 mg CD 2-6. Didn’t work so I got my period 11days ago. Started 10 mg letrozole CD 3-7 this time. I had a regular period (my normal is like 3-4 days) but I finished my letrozole already and I am still having old blood (brown) discharge daily which has never happened to me before. I have an IUI planned for the first time in 4 days and I’m worried if I am still bleeding a little bit they can’t do it. Any similar experiences?