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How do I know that I’m pregnant?

Reproductive Cycle

The reproductive period of a woman begins at menarche and ends at menopause, usually extending from 13-45 years on average, with pregnancy rare to occur under the age of 12 years and after the age of 50 years. However, there are exceptions!

Calculating Pregnancy

Pregnancy is calculated from the first day of the last period and lasts 280 days (+/- 14 days). This assumes a 28-day regular menstrual cycle. If your cycle is irregular calculations can be made to allow for this giving you your expected date of delivery (EDD).

Early Signs of Pregnancy

The first indication of pregnancy is a missed period and a time of amenorrhoea (no periods) and the pregnancy is generally confirmed by one of the many available urinary pregnancy tests. These tests are readily available from pharmacies and even supermarkets. They are very sensitive tests generally measuring the pregnancy hormone βhCG usually at a value of 50mIU/ml.

Symptoms of pregnancy 

  1. Morning sickness which in itself is a misnomer as it can occur at any time during the day. This occurs in about 70% of pregnancies and typically lasts from 5-13 weeks. A good trick to help it is to eat and drink small amounts frequently
  2. Passing urine frequently usually is a  symptom from 8-12 weeks as the womb is enlarging within the pelvis and pushing on the bladder
  3. Breast discomfort usually occurs after 6 weeks and is felt as a full feeling more commonly is first pregnancies
  4. Tiredness is frequently encountered and should not be underestimated. Remember if this occurs to rest.


Ultrasound Scans

Ultrasound is the gold standard for diagnosing pregnancy and it’s viability. A gestational sac where the baby develops can be seen on transvaginal ultrasound from 29 – 35 days post missed period, the fetal pole and fetal heart can be seen from 6 weeks post a missed period and the fetal age (gestational age) can be assessed  by measuring a Crown rump length (Baby from head to bottom) between 7-12 weeks (with a +/- 5 days). You can often see the baby moving on the scan from about 7 weeks.

There is no evidence to suggest having a scan in early pregnancy causes any issue for your baby even if the scan is transvaginal (Internal).