Confused

Paige • 23- UK. Our little pea due November2017 ❤🌈🌞
How many days after implantation bleeding did anyone get a positive on a test? My period was due on the 18th of aug (thursday) but i ended up getting a really really light bleed that lasted a day and a half and the blood was brown? On the 17th (wednesday) it started and it ended on the 18th (Thursday night). Iv also been getting a pelvic pain all weekend so went to drs this afternoon and she said it sounds like pregnancy but then she done a urine test and it came back negative so ruled it out and has taken swabs and is taking my blood to check for pcos? Im so confused because I have a period every month as normal & I conceived in January (6 weeks after getting implant removed but ended in chemical pregnancy) usually when I come on my period too I get sore breasts and cramping but iv literally had nothing this month just the brown blood and pelvic pain. Has anyone else ever experienced this or anyone have any advice? Tia x