Found this on the internet today, thought it was interesting. Means waiting till ovulation day/positive ovulation test is leaving it often too late? I just thought as soon as sperm was in there it could meet the egg: apparently not! From the Internet:
It can take up to 10 hours for a man's sperm to complete the capacitation process and be able to fertilize a woman's egg. This is why the five days before ovulation are so important. Once ovulation takes place, sperm have a very brief window of time to fertilize the egg.