Week 4

The fertilized egg has reached the uterus and embedded itself in the uterine lining. It’s now known as a blastocyst. When the fertilized egg embeds itself in the uterine lining, light bleeding known as implantation bleeding may occur. If this happens, it will be about one week before your period is due. Implantation bleeding is harmless.

The placenta begins to form around the embryo at this time. The embryo receives all its nutrients from the yolk sac.

The embryo is minuscule at this early stage of the pregnancy, and most women have no symptoms. That said, some women may already be experiencing nausea, tender breasts or very sensitive nipples.

If your period is late, you may start to suspect around the end of the week that you are expecting again. Some women “can tell” that they are expecting shortly after conception, while most feel nothing at all and suspect that to be the case only when they don’t get their period.

As soon as conception takes place, the body starts to produce a pregnancy-specific hormone called human chorionic gonadotropin (hCG). All pregnancy tests measure the presence of this hormone when you test your urine.

If you have conceived, the level of hCG in your body is so high that it can be detected by a pregnancy test around the time your period should have started, about weeks 4 to 6. If you take the test too early in your pregnancy, your hCG levels may not be high enough to allow detection. You may need to take another test a few days later if you took the test a little too early. This is to allow your hCG levels to rise enough to give a positive result.

Planned Parenthood and some clinics offer free pregnancy tests. You can also buy a test at your nearest pharmacy, in many food stores or online. The tests that you can buy are reliable.

The embryo is minuscule at this early stage of pregnancy, and few women have any symptoms. Early pregnancy symptoms include nausea, swollen or tender breasts, sensitive nipples, and changes in your sense of smell and taste. All mothers-to-be are different. Some women may at this point experience early symptoms—or they just sense that something is quite different in their bodies.

Pregnancy is typically divided into three parts called trimesters.

Trimester 1: pregnancy week 1(0+0) – 14(13+6) Trimester 2: pregnancy week 15(14+0) – 28(27+6) Trimester 3: pregnancy week 29(28+0) – childbirth

We base our calculations on the book ”Obstetrik” which is used in training Swedish midwives. Our calculation starts from the first day of your period 1(0+0).

However, there are local differences in how trimester weeks are calculated. Some sources start to calculate the pregnancy weeks from the week of conception 3(2+0), which can be a bit confusing.

The embryo is now growing in the womb and all the organs are starting to form. You may have done the pregnancy test and know a baby is on the way, or you may not know yet.

Finding out you’re going to be a parent is a life-changing experience, of course, but a negative pregnancy test can be tough for couples who have been trying for a baby for some time. Talk with each other about your thoughts and feelings—your happiness and sadness, your excitement and anxiety.