cas, yah. i got worried too.. so i called again, another nurse say maybe is mild infection. I do not have blood in pee, pee is still normal, regular flow. After resting for an hr plus and after lunch, im feeling much better, just went to pee and its fine, no pain already. But i will continue to monitor, will ask the nurse of see doc tomorrow if it worsen.
Don't feel sad, it might be implantation, like you say, keep an open mind.