If you haven’t noticed already, you probably will realise this week that your period is overdue. The missed period is often the first sign of pregnancy. You will not menstruate again until after the birth of your baby. Menstruation is interrupted by the production of a hormone called human chorionic gonadatropin (hCG). This is the pregnancy hormone which pregnancy tests detect- it is produced by the placenta and enters your bloodstream and is excreted in your urine. As hCG is only produced by the placenta and not your body, if you have hCG in your blood it means you’re pregnant or have recently been pregnant.
The purpose of the hCG hormone is to stimulate the ovary to produce the hormones oestrogen and progesterone, that are required to support the pregnancy. Had pregnancy not occurred, the levels of oestrogen and progesterone produced by the ovary would lower and you would get your period.
Most pregnancy tests check whether or not there is any hCG in the woman’s blood and the test is positive if hCG is detected. For women who are experiencing pregnancy complications (e.g. vaginal bleeding or severe cramps) the doctor may want to measure the concentration of hCG in the blood as this may help determine what is causing the complications. hCG levels that are too low or high may be a sign of miscarriage or a molar pregnancy (a pregnancy which has formed outside the womb). However, it is important for pregnant women to be aware that an unusually high or low hCG level does not necessarily mean complications. A lower than normal level may just be an indication that the pregnancy is not as far along as you thought, while a high level may indicate you are carrying twins.
In addition to a missed period and/or positive pregnancy test, other changes that you may notice include:
- Morning sickness;
- Tender breasts;
- Increased frequency of urination;
- Increasing tiredness and loss of energy.
For more information about week 6 of pregnancy
|For more information about the sixth week of pregnancy see 6 weeks pregnant|
|For more details about the changes for you baby this week see 6 weeks pregnant: Changes for baby|
|For more detailed information about pregnancy health in the sixth week of pregnancy see 6 weeks pregnant: Doctor appointments and health information|
|For a summary of the key point about the sixth week of pregnancy see 6 weeks pregnant- Key points|