HELP!!! Has anyone had this???

I am a mom of 3 kids, my DH had a vasectomy in 2003, I have regular cycles last 29-30 days. I had my AF on July 7 and it lasted until July 9th. After that I wiped clear on toilet paper, then 2 weeks after my AF, I started spotting pink and brown for 3 days, not enough for a pad or panty liner, just on toilet paper. I have had nausea, dizziness, fatigue and tender ...Is this Ovulation or Implantation Bleeding??? DH is going tomorrow to give a semen ysis test. Took a HPT 2 days ago was negative, but I'm thinking it is still too soon to get a positive anyway????