5 weeks pregnant
First trimester about 1 month
At 5 weeks pregnant, your baby is about the size of a sesame seed.
Baby this week
About 1.5–3mm. The neural tube is forming — this becomes the brain and spinal cord. Tiny heart cells have just started beating.
Did you know? The embryo's heart beats about 80–85 times per minute this week — it will speed up to over 150 bpm by week 9.
What she may be feeling
- Nausea (may be just starting)
- Breast tenderness and swelling
- Extreme fatigue
- Frequent urination
- Heightened sense of smell
- Mood swings
- Light cramping
- Implantation spotting (normal)
Tips for her this week
- Start prenatal vitamins with at least 400mcg folic acid daily if you haven't already.
- Avoid alcohol, raw fish, deli meats, and unpasteurized cheeses.
- Rest as much as you can — fatigue in early pregnancy is real and intense.
- Nausea often peaks between weeks 6–9, so be prepared for it to intensify before it eases.
For partners
- Your partner may not look pregnant yet, but her body is working overtime. Fatigue and nausea can hit hard — be patient.
- Quietly take over household tasks without being asked: cooking, grocery runs, dishes.
- Research 2–3 OB-GYNs or midwives now — first appointment is typically booked for weeks 8–10.
- Keep the news private if you haven't told anyone yet. This early window is just for the two of you.
Partner to-do list
- Research and shortlist 2–3 OB-GYNs or midwives
- Book the first prenatal appointment (target: weeks 8–10)
- Take over one household chore she usually handles
- Have a genuine check-in: ask how she's feeling and really listen
This week together
- Decide together: who to tell and when
- Review health insurance coverage for prenatal care
- Start a shared pregnancy journal or keepsake
- Download a pregnancy tracking app (Premom, Flo, or Ovia)
When to call your doctor or midwife
Contact your care provider right away, or call emergency services, if she has:
- Heavy bleeding — more than a light period
- Severe one-sided pelvic pain (could indicate ectopic pregnancy)
- Fever over 38°C / 100.4°F
- Complete absence of symptoms after week 6 — worth mentioning to your doctor
Trusted guidance: NHS: Pregnancy · NHS: Pregnancy complications · ACOG: Pregnancy · Pregnancy Info: Your pregnancy
Common questions
How big is the baby at 5 weeks?
At 5 weeks pregnant, your baby is about the size of a sesame seed. About 1.5–3mm.
How many months is 5 weeks pregnant?
5 weeks pregnant is about 1 month, in the first trimester.
What can partners do at 5 weeks?
Your partner may not look pregnant yet, but her body is working overtime. Fatigue and nausea can hit hard — be patient. Quietly take over household tasks without being asked: cooking, grocery runs, dishes.