You are 6 weeks and 4 days

Your baby's lungs won't be fully developed until late in pregnancy, but their foundations are being laid now.

234 days until your due date

This week your baby's lungs start to develop. A small lung bud branches out from the upper part of the esophagus, the tube between the mouth and stomach. This bud forms the windpipe (trachea), which divides into two main branches (bronchi) that will become the right and left lungs. The bronchi keep branching into smaller tubes, again and again.

Your baby's gut is also developing, from the mouth downward. At the start of this week, the future digestive system was a simple tube running the length of the embryo, closed at each end. It's still closed, but the esophagus has started to separate from the trachea and connect to the stomach. The swelling that will become the stomach forms around the middle of the body, then rotates 90 degrees to sit more on the left.

Buds grow from the duodenum (the first part of the bowel after the stomach) that will form the pancreas and the bile duct to the gallbladder.

In just a couple of weeks, your baby will have all its major organs and body systems.

Explainer

The shrinking yolk sac

The embryo is safely cocooned in the fluid-filled amniotic sac. The yolk sac is now attached by only a very fine thread, as the placenta gradually takes over its job.

Good to know

Ectopic pregnancy

In an ectopic pregnancy, the embryo develops outside the uterus, usually in a fallopian tube.

It can cause pain on one side of the abdomen and irregular vaginal bleeding. Some women get pain at the tip of the shoulder, thought to be caused by internal bleeding. An ectopic pregnancy can rupture the fallopian tube, causing severe pain, and emergency medical attention is essential.

If an ectopic pregnancy is suspected, you'll have a scan. Sometimes the pregnancy resolves on its own; if not, medication or surgery is needed.

As a matter of fact

Music therapy

Music therapy is a very effective way to reduce stress.

A study found that pregnant women who listened to music mimicking a human heartbeat had lower stress levels than those who didn't.

This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.