What exact day should i have sex during my clomid (clomiphene) ovulation time to concieve twins?

At Ovulation: Your best time to conceive is when you are ovulating, however there is no best time to conceive twins. You have a 5-8% chance of having twins with clomid (clomiphene). 95% of pregnancies on Clomid (clomiphene) are not twins. Whether you have twins or not depends on the number of good eggs you make, how many fertilize and implant. Good eggs are less common in 41 yr old women.