Early symptoms or just in my head?

I had unprotected sex on July 6th and 7th during “medium” and “high” chance days of conceiving according to this app assuming I was ovulating. I’ve been nauseous and cramping ever since, really. These symptoms started to occur just a couple days after the unprotected sex; however, I’ve read that early symptoms don’t appear at least until a week afterwards. Now would make sense, but not a couple days after. Is there any chance my symptoms were just extremely early or is it likely unrelated? I just got off the pill a couple months ago after being on for about 5 years.