Possible pregnancy?

I had unprotected sex with my bf on the 16th, which was also the last or day after my period. He came inside me, and now I am having some possible pregnancy symptoms. I have been nauseaus a lot and even threw up. The 27th was the last day of my ovulation and the past few days I have been having lower stomach pain, period-like cramping and sharp pain over my right ovary. Has anyone experienced anything similar, or am I just being paranoid?

Thanks!