period never came to scared to test should i test any way?

Ta
My cycle was suppose to end on Sunday but it never did come I'm afraid to test cause at times my cycle switches up on me but it'll be to soon for it to do so. I've been nauseous, body temp has been off the charts of hot and cold, very light headed and weak at times, dizziness to the Max I just don't know what to do are to think...