Last period 27th November 2020 not pregnant ?

Missing periods usually means missing ovulation if you are not pregnant.  If you don't ovulate on a regular pattern, then your period will usually remain missing until you ovulate again.  A period will happen ABOUT 14 days AFTER ovulation.

The problem with missing ovulation is that you have NO IDEA when it would be the right time to test for pregnancy.

If you have sex on a regular basis (once per week or more), then the best you can do is just test once every month whenever your period has been missing for more than six weeks.

If you don't have sex very often, then testing one time when it has been 21 days after sex would be accurate and then you wouldn't need to test again until you have more sex.  (sperm can live for up to 5 days and wait for an egg.  Once conception happens, it can take 12 to 14 days for implantation and hormones to build up.  This is a total of about 19 days - so at 21 days, a pregnancy test should be accurate.)

Contact your doctor to see if there is a medical reason for your irregular periods. 

Personally, I am now 55, so I have stopped having periods (menopause), but when I did have periods, I would average about four to six periods per year and would often have three months between periods.  I never bothered getting an actual diagnosis for my irregular periods.  I do have two children without using a fertility program.  Testing for pregnancy was always just a random guess based on how long the period had been missing.  Determining due date for the baby was never based on the last period.  It always had to be based on scans since ovulation was so much later in the cycle than what is considered "normal".  

This should not play with your anxiety at all. You should be used to it by now. According to your previous questions, you go for months without periods on a regular basis.

Go and ask your gynecologist WHY you don't have regular periods. You might have PCOS. That can't be diagnosed by amateurs on the internet.

Go see a doctor about it.  

What's your question, Sparky?