HELP ME!

My cycles are typically 33 days long. I ovulated on CD16. I had a cramps and sore breasts ever since. It's now CD28 and AF is due in the next few days. At 10 and 11 DPO I had slightly pinkish discharge and at 11 DPO I had the smallest drop of blood. Typically I do have spotting and haven't had the same amount as normal. It's much less noticeable, in fact I only noticed on 10 dpo because I BD'd with my husband and he noticed, and the next day I wiped and it was so slight. Could this have been implantation bleeding? I'm 12 DPO today and I haven't tested today but every test I've done was probably too early and also they were all negative.