4 days late- need advice!!

Mallory • 29 years young
AF was due 1/26. Nothing. Four negative tests (1 day before, 1-3 days missed) I've been unusually tired and my boobs hurt and are sensitive. Today I spotted a very, very light pink two times when I wiped and then a 3rd time was a light brown discharge. Any advice??
None of this happened when I was pregnant with my 1st so I feel like a fish out of water