Spotting after faint BFP's

[jesswishing]

Hi - I'm 99% certain im having a CP, I've been testing every day since my BFP at 13DPO with FRER and they're getting a tad darker, but not by much. Yesterday's FMU test was about 1/3 strength of control line, so I was fairly confident it would end in a CP. I went to the bathroom last night and saw some spotting on the TP, felt my cervix and there was some pink blood on it so put a pad on and went to bed - woke up and there's nothing happening. How long does it usually take to get a full on AF? Temps dropped today too