This is killing me I had sex August 17, August 28, and September 2nd. My calendar said I ovulated…

This is killing me I had sex August 17, August 28, and September 2nd. My calendar said I ovulated August 31st but I got my ovulation cramps the 2,3,4,5. I stopped cramping ever since August 29 I have been nauseous morning to night. I've had back pain for a week now. It's said its too early to test my last period started August 18th. So my calendar said I should get my period on the 15th. I can't wait to see if my period does come to see if I'm not pregnant or if I am. I took one in the hospital on Monday. But I'm still convinced that I could still get pregnant or be pregnant. Help me out please?