When is really the best time to have sex to conceive?

So I’ve been doing research and asking questions on when is the best time for sex when trying to conceive. Im 33 and I have no children and think I’m confused from all the different feedback. I was told a day or 2 before ovulation then I was told the whole time during my fertile window. So which one is it or is it another time. We’ve only been trying for 2 months but not really sure if we are even having sex at the right time.