How early did you feel symptoms that you might be pregnant?

It’s really random and maybe I’m getting sick or just worn down from going back to work this week (teacher here). I totally crashed today. Like 3 hr nap crashed. This is NOT normal for me! Ever since I woke up I’ve been a little nauseated too. My boobs started hurting a couple days ago too. I just ovulated a week ago. We had sex twice right before ovulation (Friday/Sunday...ovulated Monday).