I am very late for my period but prenancy test are negative. My last period was 26th August until 2nd September.

I am going in for a scan on December to see if there are cysts on my ovaries. Can cysts on your ovaries cause you to not have a period for so long?

What else could it be?

It can be from the cause of the cysts. Sometimes certain hormone levels will result in cysts, as a symptom. The hormone levels themselves may be what is delaying your period.

Have you had late periods once in awhile in the past or is this something new?

My periods are not very regular, but the most I have ever gone over before is 2 - 3 weeks, never two months.

Also the last period I had was very light (only when I wiped) and of a brown colour for about 14 days then it stopped and about a week later a normal flow came. That is when my Doctor booked me in for a scan

But apart from this period and the last my periods normally last about 5days.