The first week of your pregnancy is very special. And that’s because even though you are not technically pregnant you still count this week as week 1! We start counting from now because you can’t predict the exact day you conceived. But we do know that you are most fertile in the middle of your cycle when ovulation takes place.
That doesn’t mean however that you can’t become pregnant at the start or end of your cycle. Ovulation can occur earlier or later within the cycle and then you are fertile. To alleviate any doubts about when you actually conceived we start counting the pregnancy from the first day of your last menstruation. We assume that you will give birth about 40 weeks after that date. A healthy pregnancy lasts between 37 and 42 weeks.
You may have been taking folic acid because you wanted to get pregnant. Keep taking it until you are sure you have reached the 10th week of your pregnancy.
Now is a great time to calculate your fertile period.