Could I be pregnant?

I’m only 5dpo from when I think I ovulated. I had sex the first day of my fertile window and the day I was expected to ovulate. I have felt nauseous the last few days. Today, I ate so much. It’s like I couldn’t get full. My breasts are also tender. Could I be pregnant? Or is it way too soon to tell? I’m still 9 days away from my period.