When to test??🙏🏻🙏🏻

I was due on my period the 6th according to glow. It’s nearly the 12th and still nothing. I tested on Monday, negative. When should I test again?

Symptoms; loss of appetite (which I’ve only just clicked on about), I usually eat a lot and I’ve barely been eating. HEARTBURN sometimes from hell. Little cramps above my vagina on the left side very rarely or noticeable and exhausted, however I work nightshift which could be why I’m so tired. When should I test again?