Need Advice Please

TTC for 9 months and already have three kids from two pregnancies. No luck so far. Today is 8 dpo and I have really sore breast and tired. I noticed I have milky white cm but it's very wet and slippery. I took a PT yesterday it was negative but I'm not due for AF til Dec 29. What could the discharge mean? With my other pregnancies I didn't have any signs I was pregnant so I'm not sure what's to expect.