Your baby this week

Doctors count weeks 1–2 from your last period. That's before conception even happens.

You this week

There's usually nothing to feel yet. Trying to conceive? It's a good time to start folic acid.

Week 1 of pregnancy

How your baby is developing

  • Weeks 1–2 are counted from the first day of the last menstrual period, before conception has actually happened — this is the standard way pregnancy dating works.NHS

How you may feel

  • Because dating starts from the last period, there is usually nothing to notice yet — this is a good time to start a folic-acid supplement if trying to conceive.ACOG

Nutrition this week

  • Folate (B9) — supports neural-tube closure — most critical in weeks 1–12 (Leafy greens)
  • Iodine — fetal brain + thyroid development (Iodized salt)
  • Vitamin B12 — with folate, for blood + nerves (Meat)

Part of the First trimester (weeks 1–13).

Educational reference only — not medical advice. Typical/average figures; every pregnancy differs. Always consult your doctor or midwife. Seek urgent care for any warning sign.

Tips for this stage

  • Stay well hydratedSource: NHS – Have a healthy diet in pregnancy

Checklist

  • Confirm your last menstrual period (LMP) date — doctors count pregnancy from hereSource: NHS – Pregnancy due date calculator
  • Start folic acid if trying to conceiveSource: NHS – Vitamins, supplements and nutrition in pregnancy; CDC – Folic Acid
  • Book a preconception check-up if you're planning to conceiveSource: NICHD — Can you promote a healthy pregnancy before getting pregnant?