Brown Spotting 12 days before period 😱

Ke

I need help ladies, I started spotting 12 days before period. I thought I was pregnant so I went to the doctor they did pee exam also blood test it was negative. So am not sure what to do what do you think it is. And have you guys ever had this. Coz I never had this. Btw! Am married and we had unprotected sex right after my period ended.