According to healthline It’s not common for a woman to get pregnant so soon after her menstruation ends. However, pregnancy is far less likely in the first week after a woman has her period compared to the first few days or week of the menstrual cycle.
CleverLandClinic reports that a woman can become pregnant at any point during her menstrual cycle if she has sexual contact without using contraception, including during and immediately following her period. At particular times of the menstrual cycle, women are at their most fertile and therefore most likely to become pregnant.
Three to five days after your cycle has stopped are potentially fertile days. The likelihood of falling pregnant soon after a period depends on several factors, including the length of your menstrual cycle and the length of your period. Fertile days may begin as early as a few days after menstruation ends in women with lengthy cycles.
For women with short menstrual cycles, such as 22 days, ovulation can occur within a few days of the end of the period. Viable cervical mucus can keep sperm alive for up to seven days. Since this is the case, it has been suggested that women who ovulate earlier than typical may have a greater chance of becoming pregnant.
A woman may become pregnant right after her period ends if her cycle is erratic.