I can't make a recommendation on that. It depends on a lot of different things. Some people start off doing e4d. Others do one attempt for 4-6 months. It depends on your age, the other stuff you're doing to sway, and how big a hurry you are to conceive. For the most part I start urging people to go to e4d after 2-3 months, but sometimes if they were doing MORE than one attempt (like one attempt plus timing and other stuff that cuts odds of conception) I have them drop the other stuff and give one attempt a try before moving to e4d.
Now, I DO have some people do one attempt and then start e4d after that, to guard against delayed ovulation. This is a good compromise and it's something many people choose to do. Totally at your discretion if you want to do that.