am I pregnant?- implantation bleeding?

Jenna • Pcos. 4 miscarriages. Trying for a rainbow. Inactive sometimes because I am sick of the rudeness
So on about 3/11 I started having what I thought was spotting, however I'm not that sure anymore. It continued on for about 2-3 days, was dark brown (not a hint of red!), was more discharge in texture, and never stained my underwear. I looked it up online and only a few things came up. Good right? Well it's pretty much four things. Pcos related (which I have), an STD (I'm monogomous and clean, same with my boyfriend), an ectopic pregnancy, or implantation bleeding. With my pcos, my boyfriend and I don't use protection, and we are stable enough for a family. I have also been having other symptoms such as really sore breasts, nausea, headaches, and a raging sex drive. I don't want to get my hopes up that I am pregnant, but I don't want to ignore it either. Also, I was just at the doctor on 3/9 and I don't want to go for something that could be nothing. It's hard to get in as is. 
Thank you!