At the beginning of July boyfriend and I had unprotected sex. He told me that he didn't pull out fast enough and a little went in. This was the 1st or 2nd day I was completely off of my period. I've read that it's almost impossible to get pregnant the first few days after your period because ovulation is too far away, but there is still a chance. Ever since then I've felt a little off. I'm not sure if it's psychological or not. Around Monday I had some cramps, I've been extremely emotional, and today I felt nauseous. Should I be concerned about being pregnant? What are the chances?

Please and thank you for your help!

-bbvv