I Am Not Sure If I Am Pregnant. I Know

I am not sure if I am pregnant. I know that it is possible to concieve with pre cum. My boyfriend and I do not use protection and I am slightly worried considering we had sex the beginning of the second week after my period. Although he does pull out when he ejaculate I am still worried because he isn't sure if ejaculated a second time. As of today my period is late. It is rather consistent usually falling upon today or the next few days. Should I be worried?