What counts as a period?

I hope someone can help!

Yesterday was CD 28 and I had like two drops of brownish CM.
Today CD 29 I have also had creamy CM which was slightly tinged brownish.
I normally dont have this at the start of AF, its normally heavy and bright red.
My period was due today CD 29.
My boobs are quite sore and I have cramps like AF is coming.
We BD'd CD 11 and I ovulate day 12-14 (was inter-state other days bugger!)
Since ovulation I have been nausous and feeling "off colour". But last week have been feeling OK.
Not sure if its my mind playing tricks or I am pregnant (fingers crossed)
My cycles are very regular with AF turning up between CD 29-30 (last 6 months since off pill).

What do people think is the story about the brownish CM? Sorry if TMI!!!

Your advice is much appreciated!

don't know much about the brownish cm but if your period hasn't arrived by tomorrow I would be testing. Good luck :crossfingers: