help!!

so I am 19 dpo and was suppose to start my period 8 days ago. I have taken 4 tests in this past week including one this morning all have been negative. on Friday evening which was 15 dpo I had light brown discharge only when I wiped once. I don't know what all this means...has anyone else had any of this happen to them? me and my husband are trying for baby #2 and I don't know if my body is playing tricks on me bc I want it so bad. please help with any advice or experiences! Thank you