Advice?!?

Hi everyone, Sunday I took a PT and I got a BFN. Not sure if I took it too early because my cycles are irregular. Anyways, starting on the 12th I started noticing light pink blood only when I wiped but just enough to lightly stain one panty liner. As of today it’s still happening a little more so from the BD this morning. In addition, I’m having lower back pains that I don’t normally have, cramps, one sore boob lol, and heartburn. Anyone experienced this or experiencing this and got a later BFP? Or am I just overthinking and it’s just AF sneaking in.