Spotting at 3-4 dpo?

Erin

Wondering if this has happened to anyone else.......I had a positive opk on 7/11 and based on my temps I ovulated on 7/12. Then on Saturday (7/15) I had a temp decrease as well as 4-5 drops of pink when I wiped. Nothing since then and temps have gone back up. Af is not due until 7/26. I'm thinking this is too early for implantation but I've never had anything like this before. Has anyone ever had anything similar?