Hello dear, Thank you for your question and welcome to Health Care Magic. I went through your query and I understand your concern. Technically pregnancy can occur only during the fertility window in your menstrual cycle, which is five days before ovulation till the day of ovulation, and reflect the lifetime of sperm in the female genital tract (5 days) and the lifetime of the ovum (24 hours). Day one is the first day of the menstrual period and the last day is the day before the next period begins. Ovulation happens about two weeks before the next expected period. So if your average menstrual cycle is 28 days, you ovulate around day 14, and with calculations your fertility window of this month is 28 July till 2 August, so the intercourse you had on 24 July is outside this fertile window. Despite all these calculations, another fact that doesn t permit you to be pregnant, is the birth control pills you are taking. If you take the pills regularly, the chances of being pregnant are almost zero. Hope I helped with my answer. For further concerns or follow up questions, feel free to ask again. Kind Regards, Ina