Week by week pregnancy
The beginning of life:
– If 14 days after the start of your menstruation day, one of your husband testicle sperms meets with your oocyte (that is moving towards the uterus), and penetrates into it. as a result, two male and female cells combine with each other and an embryo cell will form.

– If the sperm that fertilizes an egg has an X chromosome, the baby is female; if it has a Y chromosome, the baby will be a boy.

Embryo development in the first month:
gestational age (GA) is from the first day of the last menstrual period day which includes:

Week 1: The beginning of the last period when you are not pregnant yet.
Week 2: from the end of menstruation to the day before ovulation
Week 3: Zygote formation;
The zygote enters the uterine cavity within five days after fertilization and implants in the uterus in sixth day.
Week 4: Yolk sac and placenta are forming
Some notes:

– In some women, Implantation is associated with spotting or bleeding. Do not mistake it for the last period.

– The last period should be as the same as previous periods (it means that your duration and amount of your bleeding must be like your previous periods).

If your period is late, you should take a pregnancy blood test.

Ultrasound in the first month
– Performing ultrasound is too early for the first month of your pregnancy. If you have an abdominal ultrasound, your Dr will see a thickness increase in the inner wall of your uterus, as well as in a vaginal ultrasound. A very small gestational sac can be seen too.