This pregnancy week calculator will describe you what happens in your current pregnancy period as well as give you the possible conception date. Read below the form about the early pregnancy signs.

The first day of your last menstrual period: *
Menstrual cycle length: *

How does this pregnancy week calculator work?

The health tool can estimate the gestational age of the pregnancy, the ovulation date, the fertility windows of that cycle and the possible due date. All that on two important dates you input about the menstrual cycle: The first day of the last period and the usual length of the menstrual cycle.

According to these dates the pregnancy week calculator will then estimate which was the ovulation period, therefore the time when is most likely that the conception occurred. Then you will be determined the week of the pregnancy and shown what happens during this week with the fetus.

Using the conception date and the usual estimate of a 40 weeks pregnancy you will also be given an estimate of the possible due date for the birth of the baby.

Example pregnancy week calculation:

For instance, in a pregnancy within a cycle of 28 days with the last period starting on May 16th 2014 and the current date being November 27th 2014 the result is:

■ The probable ovulation date is May 31st, 2014;

■ The fertility window is between May 27th and June 4th, 2014;

■ The estimated gestational age 27 weeks and 5 days;

■ The estimated due date is February 20th, 2015.

Week 28: By this week your baby measures about 10 inches and continues to grow and add on layers of fat. Their hair is also growing up more and more. Their senses are developed and their brain is still expanding. He or she can not only hear you but can sometimes recognize your voice although some of the fine sounds are probably muffled because of the waxy coating that still covers your baby to protect him or her.

Early pregnancy signs:

■ Tender, swollen breasts: similar or at a higher intensity than the feeling in the breasts before a period.

■ Nausea or vomiting: one of the most common pregnancy symptoms.

■ Frequent urination: these unpleasant sensations will probably increase during the pregnancy.

■ Heightened senses: a very sensible sense of smell and taste (food-cravings or food aversions).

■ Basal body temperature: a constant increased temperature for more than 2 weeks.

■ Bleeding: spotting around the time of the period.

■ Fatigue: the increased levels of hormones are an extra effort for the body.


1) Sadler TW, Langman J. (2012) Medical embryology. 12th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins

2) Moore LK. (2008) Before We Are Born: Essentials of Embryology and Birth Defects. Philadelphia, PA: Saunders/Elsevier.

3) Hunter LA. (2009) A Simple Solution to Dating Discrepancies: The Rule of Eights. Issues in Pregnancy Dating: Revisiting the Evidence. Journal of Midwifery & Women's Health 54 (3): 184–190.

04 Dec, 2014