I was post to start my period the 4th and now I'm 2days late and it moved to the 7th on ovia why did…

I was post to start my period the 4th and now I'm 2days late and it moved to the 7th on ovia why did it do that? I'm having all kinds of symptoms like frequent urination, fatigue, nausea, vomiting, cravings, pussy dry, having clear stretchy like water cervical mucus, headaches, cramps, boobs sore, stomach itching really cranky and very emotional can this be a sign of pregnancy