Missed period and negative test results

Okay ladies I posted in here a couple months ago asking if I should go to the doctor for my missed period or just wait it out to see if I would ever start, I didn’t have a period for 6 months I made an appointment to see my doctor and on that same day I started (October 17 to be exact) i had my period in November right on time and then I missed my period again for December. The whole time I didn’t have a period in those 6 months my pregnancy test came back negative both pee and blood. My period is 5 days late now and both of the pee tests came back negative. Could it be too early for the HcG to be picked up or could the same thing be happening again where I just go without a period for months on end.. my stomach will cramp here a there but not like a period cramp, and certain things make me get nauseous but I haven’t thrown up yet or woke up feeling nauseous. What’s your thought?