Your baby this week
Something incredible is happening this week. Your baby's tiny heart tube has just started to form, and in a week or so it will begin its very first beats. The neural tube — which will become the brain and spinal cord — is folding into place too, which is exactly why your folic acid matters so much right now. Your baby is about the size of an apple seed, still shaped more like a tiny tadpole than a baby, but the three main layers (that will turn into skin, muscles, bones, organs, everything) are all in place.
Your body this week
Your period is officially missed, and that positive test probably feels very real now. Early pregnancy hormones (hCG, progesterone, estrogen) are rising fast — which is why you might feel bone-tired by mid-afternoon, notice sore or fuller breasts, or get the first hints of queasiness, even without actual vomiting. Some women also report mild cramping, heightened sense of smell, or frequent bathroom trips. Eat small, frequent meals, sip water all day, and let yourself nap — your body is quietly building an entire new organ (the placenta) this week. It's a lot. Give yourself grace.
Common symptoms this week
Every pregnancy is different — you may notice some of these, all of them, or none at all. None of this is a checklist to worry over.
- Afternoon fatigue
- Sore, fuller breasts
- First waves of queasiness
- Mild cramping
- Heightened sense of smell
- Frequent bathroom trips
This week’s checklist
- Keep folic acid going every day without fail — the neural tube is closing in the next 2 weeks
- Book your first OB / midwife appointment (ideally between Week 7–8)
- Start a simple food + symptom log so you can describe things at your first visit
- Stay hydrated — aim for pale yellow urine through the day
- Swap coffee/colas for decaf or herbal alternatives (cap caffeine at ~200 mg/day)
- Be kind to your energy — early pregnancy fatigue is real, not laziness
What’s normal this week
Most of what you’re feeling is your body doing exactly what it should — the everyday symptoms don’t need a call. The signs below are the rare exceptions: noticing one doesn’t mean something’s wrong, just that it’s worth a quick check.
When to call your doctor
- Heavy or bright red bleeding, or bleeding with severe cramping
- Sharp, persistent pain on one side of your lower belly
- Severe nausea that prevents you from keeping fluids down
- Burning with urination or lower back pain (possible UTI — needs quick treatment in pregnancy)
This guide offers general information for a typical pregnancy and is not a substitute for personalised medical advice. Always follow your doctor or midwife’s guidance for your situation.
Frequently asked questions
How big is my baby at 5 weeks pregnant?
At 5 weeks pregnant, your baby is about the size of an apple seed.
What are common symptoms at 5 weeks pregnant?
Common symptoms around 5 weeks pregnant include afternoon fatigue; sore, fuller breasts; first waves of queasiness; mild cramping; heightened sense of smell; frequent bathroom trips. Every pregnancy is different — you may notice some of these, all of them, or none at all.
What is developing at 5 weeks pregnant?
Something incredible is happening this week. Your baby's tiny heart tube has just started to form, and in a week or so it will begin its very first beats.
When should I call my doctor at 5 weeks pregnant?
Call your doctor at 5 weeks if you notice heavy or bright red bleeding, or bleeding with severe cramping; sharp, persistent pain on one side of your lower belly; severe nausea that prevents you from keeping fluids down; burning with urination or lower back pain (possible UTI — needs quick treatment in pregnancy).
Last updated June 2026
References
Ovyacare’s guidance is written in-house and aligned with leading medical authorities: