Your week 21 guide

Billions of nerve cells are now connected to muscles, supporting far more active movement. Signals travel from brain to muscle along pathways that did not exist a few weeks ago, which is why movement has changed from twitching to kicking, rolling and stretching. Your baby has room to turn completely at this stage and frequently does.

Cartilage continues hardening into bone, and the bone marrow is starting to make blood cells. The marrow gradually takes over blood cell production from the liver and will be the main source by the time your baby is born. It is a handover that happens quietly over several months.

Your baby swallows amniotic fluid and passes waste into the large bowel. Swallowing helps the digestive tract develop and lets small amounts of sugar be absorbed, though nutrition still comes almost entirely through the placenta. The residue accumulates as meconium, which normally stays put until after birth.

Movement may range from gentle taps to noticeably stronger kicks. The variation through the day is normal, and your baby has sleep and wake cycles that are not aligned with yours. Many women notice more movement in the evening, partly because that is when they finally sit down.

Backache, leaking colostrum and occasional Braxton Hicks tightenings can begin. Braxton Hicks feel like a painless hardening across the whole bump that lasts under a minute and comes irregularly; contractions that become regular, painful or more frequent are different and need reporting. A small amount of colostrum leaking this early is normal and not a sign of anything starting.

Hair and nails may be growing faster than usual. This is a temporary effect of pregnancy hormones on the growth cycle rather than a lasting change. Expect noticeable hair shedding a few months after birth as the cycle returns to normal, which is alarming but not a problem.

Go through your anatomy scan results and any remaining questions with your clinician. A scan report is written for clinicians and can look alarming in places where nothing is wrong, so it is worth having the terms explained. If a follow-up scan has been arranged, ask specifically what it is looking at.

Plan leave, support and any nursery arrangements at whatever pace suits you. Some of this has real deadlines and some of it is entirely optional, and separating the two removes most of the pressure. Start with anything that has a date attached and let the rest wait. InshaAllah, separating deadlines from optional plans can lighten the paperwork.

Wear the lap belt under your bump, across your hips, and the shoulder belt between your breasts and to the side of the bump. Positioned this way, the force in a collision is taken by your pelvis rather than your uterus. Seat belts are strongly recommended throughout pregnancy, and going without one is far riskier than wearing one incorrectly.

Focus on omega-3: Long-chain omega-3 fats, particularly DHA and EPA, contribute to your baby's brain and eye development. Pregnancy-safe oily fish is one of the main dietary sources.

Walnuts, flaxseed, chia seeds and some plant oils provide a different omega-3 called ALA. These are nutritious foods, but the body converts very little ALA into DHA and EPA, so it is not a direct substitute. If you do not eat fish, ask whether an algae-derived supplement is appropriate for you.