Pregnant??

Kind of thick, kind of slime like cervical mucus. Backache. Nauseous, upset stomach. Tired. Sore breast/nipples. Mild/light cramp. Has two different period apps, one says I should've started the 25th and the other says the 28th, haven't started either days. Could I be pregnant or over exaggerating? I don't want to tell my fiancé until I officially know for sure.