<s>[INST] I had a follicular ultrasound on day 9 measuring 10mm & only one dominant follicle. I was given 75iu to wake up the follicles. I am wondering if I have a natural LH surge on day 11 that when I have a IUI on day 12 that the follicle will be big enough to get pregnant? [/INST] Hi actually your follicles don't grow that fast. It grows at a rate of 1 to 2 mm per day and it requires a follicle of more than 17 mm to get a lh surge. It will require atleast 5 to 7 days to happen from the size of 10 mm that means around day 14 to 16. you can also take a injection for lh surge when follicles become that big. Then you can have IUI the day after it. </s>