I had sex 9 days ago which was also when i was ovulating for the past 3 days so 7 days after sex i have been extremely nauseous do you think i could be pregnant ?

Yes: You could be. But nausea is very nonspecific. Could be stomach flu, reflux, reaction to meds. Take a preg test but they are most accurate when you are actually late for your period.

Possibly: This was certainly the best time to try and get pregnant. It may be too early to check a pregnancy test. Try testing your first morning urine. Otherwise, check with your doctor for a blood test.