Tmi..white discharge 3 days before AF?

This might be TMI..and I apologize i dont know all the lingo to abbreviate words so i will just say it as it is.. I'm due for my AF on the 13th.. I'm currently experincing tender and little cramping on my lower left and right sides. I never experinece this before a pd..so i'm thinking it might be it! Today when going to the bathroom i noticed some white discharge? What is this? could this be another symptom..or could it be a big let down that im not preg.. any advice, stories, personal experineces would be greatly appreciated we are ttc#1