When should I take the test?

I had sex last tuesday (drunk I know, its bad) and he tried without a condom. I yelled at him not to until he bought one. The thing is I dont remember whether he actually did it before or after he bought it. Fast forward a couple of days ago I wasnt feeling good. Not sure if its from nerves or what and today im getting a lil sick and its on my mind now. We had sex one of the final days of my period and im not supposed to get it again until the end of next month. I bought a test today. When should I take it?