A natural IUI uses a woman's natural cycle to time insemination. She and her doctor will monitor her LH hormone levels to determine when to ovulate. This usually happens around 24-36 hours after the sudden surge in the LH hormone, which indicates that ovulation will soon occur. LH hormones can be monitored using a blood test and an internal ultrasound. Intrauterine insemination is a way of affordable treatment than any other fertility treatment with a reasonable IUI cost.