A quick one: Your due date will most likely be calculated based on the first day of your LMP (Last Menstrual Period). This is because the ovulation date is difficult to calculate for many women as their menstrual cycle fluctuate every month. Since most women don’t know their conception date, the due date is thus calculated using the first day of your last menstrual period.
Due date is generally calculated counting 40 weeks starting from the first day of your LMP.
Also, Ovulation in women typically occurs 14 days before their next menstrual period, while others are earlier or later than that.
Many women have a 28-days menstrual cycle which places their ovulation to be the 14th day of their menstrual cycle. Others could be less or more than 28-days and the ovulation date changes accordingly.
For a typical women with 28-days menstrual cycle, using the first day of the LMP method, the following should be noted
Week 1: You’re definitely not pregnant since it’s the week of your menstruation.
Week 2: This is the week following your menstruation week. You’re not yet pregnant but awaiting your ovulation, a process in which the ripest of eggs in the ovary is dropped into the Fallopian tube. Luckily, the egg could get fertilized by one of the millions of sperms produced during ejaculation that travels from the vagina to the cervix to the uterus and finally landing in the Fallopian tube in order to fertilize the egg
Week 3: One of the sperms have eventually fertilized the egg. Yippee, you’re pregnant! But chill, don’t take a HPT (Home Pregnancy Test) yet as it will bring a false negative.
Your tiny bean is at its initial stage, and it’s known as blastocyst
Week 4: This marks the beginning of the embryonic stage of development. Your little one is regarded as an embryo. Its organs begin its development and at a later time, the organs will start to function.
By now, you should get a positive result from a HPT, if not, wait a few days and try again
According to BabyCentre, your baby is about the size of a poppy seed.
Source: BabyCentre App