Do cheapie pregnancy test detect HCG a day before missed period ?

Sandra

I have a 30 days cycle. My last period was on December 4th. My test came back negative on January 3rd (afternoon pee at 4 p.m.). It's the 6th of January, and I'm still waiting for my period. It is always consistent. I'm experiencing moderate cramping and my breast feels a little sore. Could I be expecting? Is it necessary for me to retest?

Thank you !