I believe that you mean your fertile period, this means the time during your menstrual cycle that you are able to get pregnant. During a typical 28 day cycle a woman would be fertile from day 7-16.
About 14 days after the first day of your period is when you are fertile.
Your first period is a fertile period. They all are. So, to answer your question, your fertile period will be February 8th.
about 14 days after the first day of your last period but only if your periods are regular
Your period can always be late whether you have sex or not. You are not likely to be fertile on the day before your period, and the fact that you used protection gives you even less reason to worry.
It means if you count the day you start your period as day 1, you are likely to start ovulating on days 14-16
about 14 days after the first day of your last period but only if your periods are regular
Ovulation occurs 14 days BEFORE your period. Unless you use fertility awareness method you can't know when you are fertile or ovulating, guessing fertile days like this is unreliable and if trying to avoid pregnancy it will fail.
if a woman has a regular menstrual period then her most fertile day is the 14th day from LMP (last menstrual period). say she has her last menstruation march 30 , she has to count 14 days from march 30 then that would mean her fertility period is April 13.
The fertile period
The possibility of getting pregnant after your period is reasonably high, but depends on your menstrual cycle. During the typical 28 day cycle a woman would be fertile around days 7-16, but if your cycle is longer you may not be fertile directly after your period.
When you're fertile depends on your menstrual cycle, you'd need to use fertility awareness method to determine exactly when you're fertile. During a typical 28 day cycle women are fertile from days 7-16 of the menstrual cycle, but again how many days after your period depends on your cycle.