pregnant?

About a month ago my bf and I had sex and he finished inside me for 9 days. We are trying to have a child but live in 2 different states so we have small windows to try. My period came on time and I got a negative at home pregnancy test. About a week ago I started to feel nauseous and even woke up in the middle of the night throwing up. More recently I've had some early pregnancy symptoms such as diarrhea, headaches, nausea, soar breast and fatigued. Can I be pregnant? What should I do? Any thoughts?