Stupid pregnancy question


I had my period September 3rd-9th on the 14th I noticed I had been extremely exhausted that day and felt kinda nauseous. Later that evening my boyfriend and I had sex and he wasn’t sure if he came or not. The whole rest of the week I was extremely exhausted and nauseous at certain times of the day. I took ovulation tests and found out I ovulated on the 17th. There is no way I could be pregnant correct? Since my symptoms were before we had sex and before I ovulated?