Thought I would have gotten my period 8 days ago- but nothin-and 4 negative pregnancy test

Heidi
Thought I would have gotten my period 8 days ago- but nothin-and 4 negative pregnancy test...then, Saturday, has small brown spotting- had implantation bleeding with DD #2, so thought possible??  Took a test this morning- BFP!!  Cycle day #39...  Here we go again!