Should I speak to a doctor?

[sashangel]

Sorry if tmi.

I have never had a period since before my daughter was born (she will be 8 in October).
I am on the contaceptive pill (cezarette. Don't know if this matters) and it has stopped my periods which I love.
However on Saturday night I had a really bad back and thought nothing else of it. During the night I had brown bitty discharge and really bad stomach cramps and back pain. I thought that was weird and had never happened before. Then yesterday I had what I would class as a mini period. It lasted for a few hours then stopped. Had more brown bitty discharge for a few hours then nothing.

Is it normal? In the 7 years I have took the pill it has never happened before.
Does your body get used to the pill?
Should I speak to a doctor about it?

[dementedpixie]

I never had proper periods with cerazette. Every so often I would get spotting that maybe lasted a day or two.