Brown spotting after fertile window

Hi everyone,

I was wondering if anyone could give me some advice. My fertile window was the 26th-31st of January. On the 31st I started spotting and for the past 6 days I’ve had brown discharge when wiping. It’s not enough to even transfer on to a pad but I’m so confused as to what is happening. My period isn’t due to start till the 12th. Now I usually get a tiny bit of spotting before my period but not 6 days before! I have no other symptoms except for the odd cramp.

Please can anyone help? Has anyone else had this before and found out they were pregnant?