AF is 5 days late and getting negative results

Hi ladies! I need some advice. I had a misscarige at the end of Oct we decide to start trying this month and I am now 5 days late and getting negative test results and had all the symptoms I've had before in my last 2 pregnancies leading up to a missed period and positive test! I'm not really stressed.. Could my body just not be ready? Has this ever happened to anyone? Thanks for any advice!