What Causes Blood Clots Before The Week Of Menstruation?

Good Day Doc



I am a 27year old female, we have been trying for a baby for about 2years now - I have an appointment with a fertility specialist on 11/03/2011.

I am expecting my next period on the 3rd March but since 8 days before my period I have this dark brown blood (only when I whipe, nothing on panty liner), it is accompanied by thick clots.



Is this something to be worried about? I normally dont have this and I have very light periods and no clots.



Thanks

Lin