Could I be pregnant ??? Help

I ovulated on the 6th, according to the app.. We had sex on Jan 31st with no BC and he finished inside me. I was supposed to start my period today and it didn’t come.. I’ve been feeling “off” the past 2 days too. Yesterday I felt sick. What are the chances that I’m pregnant? I’m gonna get a test tomorrow if my period still doesn’t come. Can sperm live that long inside me?