When should I test

Shanee
Hi I am new to this I have been having cramping and headaches for a few days. Also very tired and a huge appetite. My AF Is not suppose to start until the 5th according to my <a href="https://play.google.com/store/apps/details?id=com.glow.android">ovulation calendar</a>. Can I take the test before that or should i wait until I have missed my AF.