3 months late

i'm going on 3 months late for my period; this has never happened before...i got blood work done about a month ago and it was negative, and all my at home tests are negative

i have 0 signs of AF showing up, but these past 3 months whenever my boyfriend and i have sex, i bleed..but it's actual blood not period blood, mix between dark brown and a light ish red, and it's more just when i wipe...it's not anything crazy

thoughts? i have an appointment tomorrow where i'm gonna ask for more blood work and maybe an ultasound