Hello! My husband & I are not trying but not preventing just letting nature take its course. My AF is 5 days late & I'm around 18DPO. We DTD the day after my predicted ovulation on my calendar. I've had moderate cramping for 5 days & lots of abnormal symptoms to AF. I have taken a few tests & they're all BFNs! Today after my morning pee there was a SLIGHT tinge of a light brown on the toilet paper. Could I be pregnant? I'm on cycle day 36. Help.