insight?

AF due today and nothing yet. For the past week and a half breast more sore than normal, cramping, and backaches. Nausea started two days ago and has been on a off. Last night had pink only when wiping and haven't seen anything else since besides creamy white CM. Took a test today but was negative. Wondering if last night was implantation bleeding and I ovulated later than I thought even though I was using OPKs or what's going on. Thinking about testing again in a couple days if nothing changes. What does everyone think?