The due date is also called an estimated date for confinement. It is an estimation of the period when a pregnant woman will give birth to her baby. The due date calculator provides an approximate date for delivery of a child based on LMP ( last Menstruation Period), date of conception, ultrasound, or IVF transfer date. Among all the other factors affecting the due date, our menstruation cycle plays a vital role.


Did your date gets affected by the long cycle?

A regular menstrual cycle is normally counted for 28 days. However, it can vary from 20 to 45 days based on ovulation around the 14th day of the menstrual cycle. It is generally observed that if our cycle lasts longer, the estimated due date will also be later, and similarly, having a shorter cycle will bring your due date earlier.


How do irregular periods or long cycles calculate the due date

A couple of women have cycles that are consistently longer than the average cycle of 28 days. In such cases, the pregnancy wheel can be used, but certain simple calculations are required.


The second half of a menstrual cycle always lasts for 14 days. This is the period from ovulation to our next menstrual period. For example, if our cycle is 35 days long, we would probably get ovulated on day 21.


Long cycle effect on the gestation period

The default calculation of the due date calculator is based on the count of Last Menstrual Period( LMP) of a woman, undertaking the assumption that, on average, childbirth occurs at a gestational age ( age of pregnancy calculated from the women’s LMP) of 40 weeks or 280 days.


Though there is some debate regarding when a pregnancy technically begins.Whether at fertilization age(Conception) or when the egg gets adheres to the uterus(implantation). However, gestational age does not vary based on different definitions as it is based on.

Considering gestational age, pregnancies typically last between 37weeks to 42 weeks, while 40 weeks are normally estimated for calculations. Therefore, the due date is usually estimated by calculating the date, which is 40 weeks from starting a women’s LMP.


Suppose, if we had a cycle of 35 days, then we would be in effect three weeks pregnant at that stage as the due date would be moved a week forward, taking into account a later evolution, which leads to conception. Hence, The length of the cycle will push forward the time of ovulation.


Calculation Of Long Cycles On Pregnancy Calculator 

Once you get an idea of the ovulation time, an adjusted LMP can be used to estimate the due date with the pregnancy calculator.

Taking an example, if your menstrual cycle is 35 days long and the first day of your LMP was November 1, then:


Adding 21 days =November 22. Subtracting 14 days to find adjusted LMP date= November 8.


Once you are done with calculating the adjusted LMP date, Mark it on the due date calculator and then observe the date where the line crosses. This will be the estimated due date, resulting from the period of the menstrual cycle.