Is it implantation? Am I pregnant?

Sierra

Hello everyone. I normally have a 27 day cycle. My last normal af was on 10/4 and lasted the normal 5 days, heavy as always. I knew my fertile window was between 10/16 & 10/22. I baby danced on 10/21 and 10/22. My next cycle was due 10/31. Normally I have sore boobs and cramping the day before AF but none of this happened. I spotted for 3 days. Day 1 was light pink, day 2 was brown, and day 3 was so light the pink blood was only on the tissue until noon. Spotting was on and off. I’m under the impression it was possibly IB but I have yet to get a BFP. I have been exhausted, constipated, cramping, having headaches, and lately my boobs have been sore. Went to the ER days ago was tested for thyroid issues and a urine test was done but she said everything came back normal. Sent me home with a hpt and told me to try doing a urine test in a week or so. I’m not a first time mom and honestly I believe I am pregnant. So lost at this point, I’d like some insight until I can get some concrete answers.