Pregnancy calendar
Calendar dates
- First day of last menstrual period-
- Estimated conception-
- Due date-
Baby size this week
- Length-
- Weight-
Current progress
- Weeks pregnant-
- Months pregnant-
- Trimester-
- Days passed-
- Days left-
- Progress-
Pregnancy or gravidity is the time when (an) eggcell(s) is fertilized by a sperm, which then develops into an embryo and subsequently a fetus. On average, the pregnancy lasts for 40 weeks before delivery. This Convertworld pregnancy calendar can help you to estimate the different stages of the pregnancy.
| Trimester 1 | Month 1 | Week 1
| Week 1 | First day of last period |
Week 2
| Week 2 | |||
Week 3
Fertilization of the ovum to form a new human organism, the human zygote. (day 1 of fert.) The zygote undergoes mitotic cellular divisions, but does not increase in size. This mitosis is also known as cleavage. A hollow cavity forms marking the blastocyst stage. (day 1.5-3 of fert.) The blastocyst contains only a thin rim of trophoblast cells and a clump of cells at one end known as the "embryonic pole" which include embryonic stem cells. The embryo hatches from its protein shell (zona pellucida) and performs implantation onto the endometrial lining of the mother's uterus. (day 5-6 of fert.) If separation into identical twins occurs, 1/3 of the time it will happen before day 5. | Week 3 | Your baby's conceived | ||
Week 4
Trophoblast cells surrounding the embryonic cells proliferate and invade deeper into the uterine lining. They will eventually form the placenta and embryonic membranes. The blastocyst is fully implanted day 7-12 of fert. Formation of the yolk sac. The embryonic cells flatten into a disk, two cells thick. If separation into identical twins occurs, 2/3 of the time it will happen between days 5 and 9. If it happens after day 9, there is a significant risk of the twins being conjoined. Primitive streak develops. (day 13 of fert.) Primary stem villi appear. (day 13 of fert.) | Week 4 | |||
| Month 2 | Week 5
A notochord forms in the center of the embryonic disk. (day 16 of fert.) Gastrulation commences. (day 16 of fert.) A neural groove (future spinal cord) forms over the notochord with a brain bulge at one end. Neuromeres appear. (day 18 of fert.) Somites, the divisions of the future vertebra, form. (day 20 of fert.) Primitive heart tube is forming. Vasculature begins to develop in embryonic disc. (day 20 of fert.) | Week 5 | Positive pregnancy test | |
Week 6
The embryo measures 4 mm (1/8 inch) in length and begins to curve into a C shape. The heart bulges, further develops, and begins to beat in a regular rhythm. Septum primum appears. Branchial arches, grooves which will form structures of the face and neck, form. The neural tube closes. The ears begin to form as otic pits. Arm buds and a tail are visible. Pulmonary primordium, the first traits of the lung appear. Hepatic plate, the first traits of the liver appear. Buccopharyngeal membrane ruptures. This is the future mouth. Cystic diverticulum, which will become the gallbladder, and dorsal pancreatic bud, which will become the pancreas appear. Urorectal septum begins to form. Thus, the rectal and urinary passageways become separated. Anterior and posterior horns differentiate in the spinal cord Spleen appears. Ureteric buds appear. | Week 6 | |||
Week 7
The embryo measures 9 mm (1/4 inch) in length. Lens pits and optic cups form the start of the developing eye. Nasal pits form. The brain divides into 5 vesicles, including the early telencephalon. Leg buds form and hands form as flat paddles on the arms. Rudimentary blood moves through primitive vessels connecting to the yolk sac and chorionic membranes. The metanephros, precursor of the definitive kidney, starts to develop. The initial stomach differentiation begins. | Week 7 | |||
Week 8
The embryo measures 13 mm (1/2 inch) in length. Lungs begin to form. The brain continues to develop. Arms and legs have lengthened with foot and hand areas distinguishable. The hands and feet have digits, but may still be webbed. The gonadal ridge begins to be perceptible. The lymphatic system begins to develop. Main development of external genitalia starts. | Week 8 | |||
Week 9
The embryo measures 18 mm (3/4 inch) in length. Fetal heart tone (the sound of the heart beat) can be heard using doppler. Nipples and hair follicles begin to form. Location of the elbows and toes are visible. Spontaneous limb movements may be detected by ultrasound. All essential organs have at least begun The vitelline duct normally closes | Week 9 | |||
| Month 3 | Week 10
Embryo measures 30-80 mm (1.2-3.2 inches) in length. Ventral and dorsal pancreatic buds fuse during the 8th week Intestines rotate. Facial features continue to develop. The eyelids are more developed. The external features of the ear begin to take their final shape. The head comprises nearly half of the fetus' size. The face is well formed The eyelids close and will not reopen until about the 28th week. Tooth buds, which will form the baby teeth, appear. The limbs are long and thin. The fetus can make a fist with its fingers. Genitals appear well differentiated. Red blood cells are produced in the liver. | Week 10 | ||
Week 11
| Week 11 | Your baby's heart beats | ||
Week 12
| Week 12 | |||
Week 13
A fine hair called lanugo develops on the head. Fetal skin is almost transparent. More muscle tissue and bones have developed, and the bones become harder. The fetus makes active movements. Sucking motions are made with the mouth. Meconium is made in the intestinal tract. The liver and pancreas produce fluid secretions. From week 13, sex prediction by obstetric ultrasonography is almost 100% accurate. At week 15, main development of external genitalia is finished | Week 13 | |||
| Trimester 2 | Month 4 | Week 14
| Week 14 | |
Week 15
| Week 15 | The riskiest period is over | ||
Week 16
| Week 16 | |||
Week 17
| Week 17 | Having a boy or girl? | ||
Week 18
| Week 18 | |||
| Month 5 | Week 19
Lanugo covers the entire body. Eyebrows and eyelashes appear. Nails appear on fingers and toes. The fetus is more active with increased muscle development. "Quickening" usually occurs (the mother and others can feel the fetus moving). The fetal heartbeat can be heard with a stethoscope. | Week 19 | Feel your baby kick | |
Week 20
| Week 20 | Your baby hears sounds | ||
Week 21
| Week 21 | |||
Week 22
| Week 22 | |||
| Month 6 | Week 23
Eyebrows and eyelashes are well formed. All of the eye components are developed. The fetus has a hand and startle reflex. Footprints and fingerprints continue forming. Alveoli (air sacs) are forming in lungs. | Week 23 | ||
Week 24
| Week 24 | |||
Week 25
| Week 25 | |||
Week 26
| Week 26 | |||
Week 27
The brain develops rapidly. The nervous system develops enough to control some body functions. The eyelids open and close. The cochleae are now developed, though the myelin sheaths in neural portion of the auditory system will continue to develop until 18 months after birth. The respiratory system, while immature, has developed to the point where gas exchange is possible. | Week 27 | |||
| Trimester 3 | Month 7 | Week 28
| Week 28 | Your baby can breathe |
Week 29
| Week 29 | |||
Week 30
| Week 30 | |||
Week 31
The amount of body fat rapidly increases. Rhythmic breathing movements occur, but lungs are not fully mature. Thalamic brain connections, which mediate sensory input, form. Bones are fully developed, but are still soft and pliable. The fetus begins storing a lot of iron, calcium and phosphorus. | Week 31 | |||
| Month 8 | Week 32
| Week 32 | ||
Week 33
| Week 33 | Your baby has fingernails and toenails | ||
Week 34
| Week 34 | |||
Week 35
Lanugo begins to disappear. Body fat increases. Fingernails reach the end of the fingertips. A baby born at 36 weeks has a high chance of survival, but may require medical interventions. | Week 35 | |||
Week 36
The lanugo is gone except on the upper arms and shoulders. Fingernails extend beyond fingertips. Small breast buds are present on both sexes. Head hair is now coarse and thickest. | Week 36 | |||
| Month 9 | Week 37
| Week 37 | ||
Week 38
| Week 38 | Your baby is full-term | ||
Week 39
| Week 39 | |||
Week 40
| Week 40 | Your baby's due next week |
This pregnancy calculator offers estimates based on your input. Pregnancy length varies, and due dates are approximate. For medical guidance or accurate dating, consult your healthcare provider.