How do you mamas know if you are in early labor... I have been induced and had a c section so I…

How do you mamas know if you are in early labor... I have been induced and had a c section so I never really experienced early labor... I have terrible back pain and on and off cramping in my front. I took a hot bath and nothing has really changed. Plus I feel like I am sick, sore throat, chills and very nauseated. Please any advice? Oh and I'm 35 weeks