They have ovulation kits at the store. It’s better to have sex before ovulation. After ovulation, a woman’s egg only survives for a day, but a man’s sperm can live in a woman for 3 - 5 days, so having sex leading up to ovulation will increase the amount of sperm that could potentially fertilize the egg once it drops.
Good luck! :)
every person is different. your best option is to get a home ovulation kit