How long is this supposed to take?

Nobody tells you the shape of this, so every month that isn't the one feels like evidence. Here's the actual curve, from a prospective study that followed 340 couples using timed intercourse.

Moderate evidence Two things are worth taking from that chart, and they pull in opposite directions on purpose.

First: one cycle is not a referendum. Even among couples with no fertility problem whatsoever, only about 38% conceive in the first cycle. The most likely outcome of any given month is that it doesn't work. That's the base rate, not a signal.

Second: the curve flattens. Most of the couples who are going to conceive on their own have done it by six cycles. The authors of that study put it plainly: after six cycles of well-timed trying, roughly every second couple still waiting is subfertile or infertile. The steep part is behind you by then, and "just keep trying" starts quietly costing you time.

How that squares with the twelve-month rule

If most people conceive by six cycles, why do guidelines say to wait twelve before an evaluation if you're under 35?

Because both facts are true. The curve is much flatter after six cycles, but it hasn't stopped — another chunk of couples conceive between six and twelve months without any help. Twelve months is where the balance tips from "still statistically normal" to "worth investigating." It's a threshold for action, not a prediction about you.

And the threshold moves with age, because the cost of waiting does:

• Under 35: evaluation after 12 months.
• 35 to 39: after 6 months.
• 40 or over: right away, no waiting period.
• At any age, sooner if there's a known reason — irregular or absent cycles, a history of pelvic infection or surgery, known or suspected endometriosis, prior pregnancy loss, or a partner with a known issue.

What's reasonable to do in the meantime

Timing well is the highest-yield thing available to you, and most people are doing less of it than they think. Beyond that, the list of things with real evidence is short and worth doing, and the list of things being sold to you is long and mostly isn't.

• Know when you're ovulating and cover the window.
• The short list of basics, and what actually helps beyond them, sorted by how good the evidence is.
• Both of you — roughly 40 to 50% of cases involve a male factor, and the test for it is simple.