HELP!!!!

so i hope i dont sound clueless when i post this but im very very confused. im on birth control and my S/O and i always have unprotected sex. but for the past few months i had been getting heavier spotting in between my 28 day cycle, and i went to my obgyn and she prescribed to up the dosage of my bc. i havent started it yet since i had been mid cycle into my old one. but when i was supposed to be due for my period (when i began taking the placebos), it didnt "start up" until my 3rd day taking the placebo (i take the 4 day placebo pack). now i put quotes around 'start up' bc it was very unusual bleeding. i very very lightly spotted and for days i had been excreting brown, old blood as discharge, when ive never missed a period and it is always heavy when my period is due. so my s/o snd i went out to get a pregnancy test and i took it at around 7:30-8:00 pm only to have absolutely no result. no lines, no fades, nothing. as if i had never urinated on it. i checked back on it 30 or so minutes later and it had the two faint lines (the test on the bottom), now my heart dropped and i started panicking but as i read up on it i found that it can either be a faint positive result or just an evaporated line. so i decided to take the second test in the morning so i can use my first morning urine as it has the most hormones in it. so i took it and within seconds, i got that cold, hard, definite negative with a thick ass line. i know i should go w the second test bc it tested so quickly and had a thick line but ive also heard of false negatives being highly possible while false positives are very rare. and also if it is negative, it still doesnt explain my very very light "period". im very very confused. it'd be incredibly amazing if one or a few of you fellow eve members could help.

also these photos are what my periods have been like since it started in june