Can I be pregnant?

Corina • Im 19 and a single teen mommy to a beautiful baby girl that I love with all my heart.
Hi my name is Corina and I am 18 years old and my boyfriend is 19 years old and my last period was on September 23, 2014 and my ovulation date was October 7, 2014 and my boyfriend and i had unprotected sex, and he ejaculated inside me on that night.  And my doctor said that there is a very huh chance that i could be pregnant. Do you think i can be pregnant? Cause my doctor said that we did it at the right time. But I'm still worried?