Please let me know if you’ve had something similar and are pregnant!

Period due today, I had spotting 3 days ago only a couple times when I wiped it was dark brown and stringy, the next day only a light pink smudge once, and the day after that dark brown/bright red like a light period. I’ve taken like 6 test and they have faint lines. I’m not sure what’s going on is this a chemical or implantation bleeding? My breast have been sore, I’ve been cramping on one side and in my back, and have been nauseous. Also my urine is dark orange/brown looking could I have a UTI and that be causing the bleeding?