Had unprotected sex on the 14th while I was ovulating. On the 17th I feel my breast has gotten a little fuller and I feel bloated. Pregnant or not?

A coincidence. There are no pregnancy-caused symptoms that occur 3 days after sex. Any symptoms would not be due to a newly conceived baby... it's just way too soon, as there are no changes in one's body yet. That means one has to look for other causes of her symptoms.