I need some answers!

I have ALWAYS had a regular period. So regular, that I typically know exactly what day it'll show up. I am 4 days late and I don't have any signs of it coming. I tested about two days ago and received a negative. Last night both boobs started leaking clear and white. Not a large amount but I've never had that happen before. Waited until the morning to test again, but still received a negative. What the heck is going on?! This would be my second pregnancy. I stopped breastfeeding my son about 11 months ago. Is it possible that I'm pregnant but still getting a negative?