What is going on? Advice

I am exactly 3 weeks late for my period today and for 2 and half weeks now I have had the worst indigestion and even waking from it, I have thin white milky discharge and a fair bit of it (keep thinking I have my period and go and check and it’s discharge). Over the past week my skin had broken out in pimples, just my nipples were sore until last night, now my boobs are swollen and very sore. I’m so tired, more than usual but all of my tests have been negative. Has anyone been this late and gone on to be pregnant?