Possible implantation bleeding

Hi all, I have been bleeding for five days now. The color is brown and pink-ish, just like implantation bleeding is described. My last period started on July 11th and my next is nort due till Aug 8th.. I am not spotting, but this is lighter then my regular period and I have always had very regular cycles. I have not had unprotected sex, but a condom is not 100% save. That was in the week before this bleeding started. Twice. I did a test on day 3, saturday. It came out neg. I've been having light cramps and been feeling nauseous on 2 occasions. Having back pains and headaches. I have discovered a swollen lymph node in (sorry, I don't know the name of it and can't reach Google or a dictionary) the left side of where my torso and leg meet.. I suffer from hidradenitis supperativa, which might be the cause of this, but it can also be a sign of an infection in my reproductive organs. I am worried sick! If I might be pg, me and my boyfriend will fully accept that, so that is not a big issue.. Not knowing why I am bleeding is worrying me so much. I have an appiontment at the doctor today and am very anxious about it! Before I go, I'll take another test and see what it says.. I will post an update of any results. Just thought I'd share my experience. What are your thoughts on this? If I had some sort of infection, would the blood be the color that it is? Would I be having all the other signs of pregnancy? Thanks for any replies!:)