The first week of pregnancy is usually silent and passes off without any prominent signals. Your pregnancy begins on the day one of your menstrual cycle. Even though you have not conceived yet it is still considered as the start of your gestation period. Conception takes place approximately 14 days after the start of the cycle. Changes that happen to your body There are a lot of hormonal changes that happen to your body. To help your uterus house the fertilized cell after conception the progesterone levels increases in your body which in turn make the endometrium the inner lining