Hallow dear, I have understood your concern. Usually the follicle is mature to release healthy egg at 18 mm size. Inj. hCG was given to you when the follicle was 18 mm size. So it was well the timed. The egg is released usually within 24 hours of hCG injection. Hence, immediately on the next day, very rightly IUI was performed. Now daily intercourse for two days after that is advised for additional coverage, in case the egg is released late. After the ovulation life of an egg is 24 hours. So any intercourse after that may not be of use from fertility angle. Continuation of ultrasonography for confirmation of ovulation might have been useful to decide how long daily or alternate days intercourse is to be continued. However, there is no harm in continuing daily intercourse even otherwise also. I hope I have clarified your doubts. This information may be useful to you if needed (which I wish should not be required) for future cycles.