Hi and thanks for asking us on HCM. Unprotected intercourse at any time of the month, even during your period, always carries a risk of pregnancy. Sometimes, after fertilization (sperm meets egg) and implantation of the fertilized egg into the lining of the uterus, light bleeding can happen. This is called an implantation bleed. Symptoms of early pregnancy include nausea, vomiting and abdominal cramps. So, yes, there is a possibility of pregnancy. Home pregnancy kits are a convenient but inaccurate way of testing to see if you have fallen pregnant. The most accurate method is to have your family doctor perform a blood test known as serum beta HCG. I hope I have answered your question satisfactorily. Take care. Dr Shabnam