PLEASE HELP! How long should I wait to test??

I am currently 3 weeks late on my period.. I took a test last week that came out negative and I don’t have any symptoms of being pregnant besides my missed period.. I got off my birth control in the beginning of December so I’m not sure if that has messed up my cycle or if I actually have a chance of being pregnant.. I don’t have any spotting or cramping so I’m basically living a girls dream of being period free lol. opinions?? Do you think my cycle is off or should I keep testing even though I don’t have any symptoms of pregnancy...HELPPP