The Female Atlas
By The Female Atlas team · early stages desk
Published 2026-11-15 · Updated 2026-11-15
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Trying to conceive: where to start

If you're trying to conceive, the numbers are kind: more than 8 in 10 couples where the woman is under 40 conceive within a year, NHS figures show, and a normal cycle runs 21–35 days. Our guide to the reproductive years gives the wider picture.

This page holds the key numbers and plain answers to common period questions. A sensible point to ask for help is after 12 months of trying in the US, or 6 if you're 35 or over; the NHS suggests a GP after a year, sooner from 36.

Facts

A normal cycle; changes are worth tracking and checking 21–35 days
NHS, Periods · 2024
Daily folic acid, from 3 months before trying until 12 weeks of pregnancy 400 µg/day
NICE PH11 and NHS: folic acid and vitamins before and during pregnancy · 2008
Folic acid start (US) at least 1 month before conception
CDC, Folic Acid: About · 2024
When to ask for help (US); UK: GP after 1 year, sooner from 36 12 months; 6 months if 35+
CDC, Infertility FAQ · 2024
Couples (woman under 40) conceiving within a year more than 8 in 10
NHS, Infertility · 2024
Usual period length 2–7 days (about 5)
NHS, Periods · 2024
Heavy bleeding signs: pad or tampon changes, clot size (10p coin), duration every 1–2 hours; over 2.5 cm; longer than 7 days
NHS, Heavy periods · 2024

Common questions

Why are my periods so heavy?

This is a common worry, and not one to just put up with. The NHS signs are changing a pad or tampon every 1–2 hours, clots larger than about 2.5 cm (a 10p coin), or bleeding beyond 7 days. A provider can look for the cause with you.

Is missing a period normal?

When you're trying to conceive, a missed period may be the news you hoped for, so a pregnancy test is a good place to start. The normal range is wide, so a period can feel late and still be on time. Repeated misses are worth checking.

Why is my period brown on the first day?

Color on its own isn't among the signs the NHS lists for heavy bleeding; those are about how much and how long. If first-day brown blood comes with pelvic pain or irregular cycles that persist, it's worth asking your provider for a referral.

Is it normal to feel nauseous on your period?

Many readers ask about feeling sick, or even throwing up, around a period. The clearest guide is how much it disrupts you: if nausea, vomiting or pain stops you going about your day, that's when to see a doctor. A note of which days helps.

Why is my period longer than normal?

A period usually lasts 2–7 days, about 5 on average, the NHS says, so a day or two more than your usual can still be normal. Many women find that noting the first and last day for a few cycles makes any pattern clear.

Next steps

A good place to start is the question on your mind today, with daily folic acid if pregnancy is the plan. This is not one size fits all, so you decide what fits you.

Sources

The guidelines and studies this page draws on.

  1. Periods, NHS (2024)
  2. Heavy periods, NHS (2024)
  3. Infertility, NHS (2024)
  4. Infertility FAQ, CDC (2024)
  5. Folic Acid: About, CDC (2024)
  6. NICE PH11 and NHS: folic acid and vitamins before and during pregnancy, NICE and NHS (2008)