Possible implantation bleeding and therefore pregnant? Help!

Tara

So I'm hoping with everything I say and list someone out there can give me some help/guidance/tips. First, I'm 38 and never been pregnant and I have PCOS. Secondly, even though I have PCOS my periods are pretty spot on; occasionally I will have a case where I start a couple of days late or will spot and then come on regularly. Saying all of that as a precursor to currently what is going on: I was due to start on May 24th and on May 25th I had a couple of drops of blood in the toilet and that was it until the 27th when I wiped and it darkish red/brown color and since then, maybe once a day, when I go to the bathroom and wipe there will some light pink stain on the toilet paper. Also my symptoms have been ranging from really tired, to bloated(I have gas all the time it seems, especially at night), to back pain, light cramping/upset stomach, to achey breasts. I took a dollar tree pregnancy test on the 27th and it came up negative, but my friend said it was probably still too early to test. Just wondering if anyone else, especially those who have dealt PCOS, had these issues and ended up NOT being pregnant. I'm planning to get another test and it take later this week (any recommendations on the best brand are welcomed). THANKS to all those who take the time to read and respond!