HELP? 2WW Need advice

courtney🌻 • 21. Lucas Michael & Liam Scott - 9.25.15
Very light spotting from 4dpo to 8dpo. What could this mean? I've never had spotting mid cycle and I always thought implantation bleeding was only for like 12-24 hours. 
One day the bleeding was bright red (picture attached) but every other day it's been light pink and only visible for about two bathroom breaks. The bright red bleeding only showed when I wipe once. 
Currently 8 dpo and my symptoms are:
Slight nausea
Extreme breast and nipple pain
Fatigue
Moderate cramps (feels like when I had my iud)
And a weird craving for lemons.