spotting

cam someone give me their opinion. I always know when I'm going to start by my CM. the day before I have none. I've been having a watery CM for the last few days even today, get home after work and there is pink blood on my panties and very very little on the toilet paper. I have felt good in over a week from nausea to being exhausted. I've literally had no symptoms of my cycle like normal. Could it possibly be implantion bleeding? I have 3 kids and do t ever remember having it before