Is this normal?

DH and I had sex at the peak of my ovulation. That was 5 days ago. For the last 3 days I've been exhausted, moody, cramping, and having heartburn. My heartburn is gone but now I've got extreme nausea to the point where I can't finish a meal. Is that a normal sign of pregnancy or could I have the flu. This seems early to have symptoms and my breats aren't sore. I just don't want to get my hopes up.