Brief Answer:
The success rate of IUI is quite low.

Detailed Answer:
Thanks for asking on HealthcareMagic. I have carefully gone through your query and understand your concerns. There are multiple things that you need to understand. Let me put them one by one:
* Usually the ovulation takes place around 15th day of the cycle. But it may vary to some extent. The status of ovulation may be monitored by folliculometry. But the ovulation could occur before the next folliculometry and all that is detected is that ovulation has already occurred. The ovum is alive for only 24 hours. Unless the IUI is done at the right time and unless the sperms are able to fertilize the ovum within that 24 hours window, the IUI cannot be successful. The success rate of IUI is something like 25% only. That means, of four attempts only one attempt is likely to be successful.
* Multiple factors need to be kept in consideration. The health of the semen, the level of monitoring, the identification of the exact offending factors, and more. Unless all are at a balance, success is unlikely.
* You could discuss your scenario in detail and I could try to offer more specific suggestion. Please mention the duration of your attempts to conceive, the pattern of having unprotected intercourse, the regularity of your cycles, as well as the results of the semen analysis.
I will await your response.
Regards

---