It's by far not a definite sign of
pregnancy. No symptom means you're pregnant--because you don't even need symptoms to be pregnant. That's the one problem many women put far too much importance into. It's assumed to be pregnant you have to have fatigue, nausea, sore breasts, larger breast size, back ache, cramping, headache, frequent urination
, eating more/less, etc etc etc. In reality, many women get no symptoms at all and symptoms don't indicate you're pregnant nor the health of a pregnancy.