Hi My Name Is Felicia And My Boyfriend And I

Hi my name is Felicia and my boyfriend and I had sex August 2nd he came in me. I was suppose to get my period August 3. Well; I heard from online u can ovulate 5 days before and 5 after. I took a pregnancy test and it came back negative. My period was late 4 days. I got it the 6th of August and lately I have Been feeling really nauseous and my sense of smell has highly increased. What do I do? My boyfriend and I have been planning a baby