WTH?

Ok so I am at work here freaking out, I just went to the bathroom and when I wiped there was dark brown blood. I am hoping this is implantation spotting, I never spot before I have a period, unless its been six months or more since last period and its just spontaneous bleeding because lining is so thick from not have a period for so long. In this case not the problem been having medically induced periods since december. Now my question is does this mean the embies just implanted so it would be two days before I see anything on a hpt, or if I took one now it would show up.

The symptoms I have been having are the usual cramping for two days after transfer, my left side feeling like I pulled a muscle, then since tues if I don't eat within hour after waking up my stomache cramps(I am not a breakfast eater, I usually do not eat until noon which is my lunchtime at work) and I feel like I haven't ate for days. on Wed my sister made a salad for dinner and I thought I was going to barf looking at it, I had to leave. yesterday I was just feeling nauseous, and when her boyfriend got in car after smoking I was dizzy smelling the smoke come off of him.