4 weeks pregnant: fertilisation, symptoms and tips

At this early stage, your baby is so small that it couldn’t be picked up by a regular ultrasound scan. It’s less than half a millimetreacross, but very busy forming links with your blood supply and developing the cell layers that will soon become its organs, muscles and bones.

At 4 weeks, levels of the pregnancy hormone HCG (Human Chorionic Gonadotrophin) will be high enough to return a positive result on a pregnancy test. HCG levels rise after conception, telling the body to prepare for pregnancy, begin developing the placenta, and stop menstruating.

The placenta has not yet started forming, so at the moment the embryo is getting its nutrients from a little yolk sac. In a few weeks, though, the placenta will start to grow, and it will keep growing until week 18 – 20 of your pregnancy, when it will be fully formed.

Even now, the embryo is tucked inside the amniotic sac that will keep your baby safe from infection until birth. It’s amazing to think how it will grow over the next several months!

Some people experience symptoms of implantation at 4 weeks pregnant, including light cramping and spotting or bleeding. On the other hand, some people don’t notice implantation at all. Remember, your body is changing on the inside, even if you can’t see anything on the outside. So, if you notice increased vaginal discharge, or sore or tender breasts, these might be symptoms of your body adapting to the pregnancy.

Mood swings

In addition to the physical symptoms, the increase in pregnancy hormones could leave you feeling emotional, moody, and even forgetful. Many of these early pregnancy symptoms mirror the symptoms you might usually experience when you’re expecting your period, so it’s easy to see how those people who aren’t actively trying to conceive might miss them altogether!

However convincing your symptoms are, always confirm with a pregnancy test to be sure.

To ensure you and your baby have all the nutrients you need to support a developing embryo, it’s important to take folic acid supplements during the first 12 weeks (first trimester) of pregnancy. There are additional supplements you should take throughout pregnancy, such as vitamin D. You can find a full list of recommended supplements in our pregnancy supplements guide.

Or you may find it simpler to take a multivitamin especially designed for pregnancy, so you’ve got all your bases covered.

Healthy eating during pregnancy will also ensure you have the stamina required to get through nine months of growing a baby, not to mention birthing one!

The best pregnancy diet is well-balanced, with a good range of protein, carbohydrates, healthy fats and fruit and veg. Of course, treats are not off the menu – just try to ensure a healthy balance across the week. Our guide to what to eat during the first trimestercan help if you’re stuck for recipe inspiration.

You’re unlikely to have any prenatal appointments just yet, but it is worth scheduling a booking-in appointment with your midwife for a few weeks’ time.

How many months is 4 weeks?

At four weeks pregnant, you are around one month pregnant. Only eight more months to go!

What should I be feeling at 4 weeks pregnant?

Physically, there will be very little to feel at 4 weeks pregnant. You may feel some cramping during implantation, and your breasts might feel tender, but other than that you should be largely symptom free at this point in your first trimester.

Emotionally, it might be a different story. If you are riding the hormone rollercoaster, you might find your emotions sit much closer to the surface than usual. Talk to your partner and explain how you’re feeling so that they can support you. Many people feel anxious at this early stage in a pregnancy – for a number of reasons. It’s always best to share these feelings with someone you trust.

Where is the baby located at 4 weeks?

At 4 weeks, the baby will most likely have made its way into your uterus and implanted in your uterine wall.

Can you go in a hot tub at 4 weeks pregnant?

The NHS advises that it is possible you could overheat in a hot tub, sauna, jacuzzi or steam room, and that raising your core temperature could be harmful during the first 12 weeks of pregnancy. Therefore, it is probably best to avoid hot tubs, or water above 35˚C (e.g., in a hydrotherapy pool).

Is cramping normal at 4 weeks pregnant?

Implantation cramping is normal, but it is not usually severe. If you are experiencing severe cramping, talk to a health professional. This could be a sign of an ectopic pregnancy.