Earliest sign of pregnancy?

What was your earliest sign of pregnancy? I'm just getting on track after BC and not sure if I ovulated last week or the week before....so not sure if my period is supposed to come this week or next. I've just been fatigued worse this week than when I had the flu! And nauseous/moody. Can't tell if I'm getting sick orrr maybe pregnant. Waiting til this weekend to test and see what happens!