Hello there. I can understand your concern. I want to know if your periods are always on time? The time of the cycle also matters, you did it in a time when you are not fully fertile, it can be said that you are semi fertile in that time. In semi fertile days, the chances of getting pregnant are less, about 45-50 percent itself. Also you say that he didn't ejaculate inside you so, the chances decreases even further. Just wait for a few days, it may sometimes delay for even upto 15 days. Don't need to worry about it. May be next time, you can use something called a CONDOM. Best regards. Dr. Anil Kumar Jain.