Confused what to do

Kimberly

Ok so my period is 6 days late no symptoms exept for tiredness lower back pain and mood swings but I'm bipolar so could be that took a test last night it was negative having cramps off and on not consistent really not sure how to handle this my periods are pretty normal and consistent when is right time to take a test? Could this be implantation ?there's no spotting no blood nothing advice ladies