Implantation at 12dpo possible?

Today I woke up to light brown spotting (only on the toilet paper). It went away by early afternoon, and I have no cramping.

Today is 10-12 DPO (my last positive opk was last Thursday but my temp increased that same day 🤷🏼‍♀️). I've never spotted before without it quickly turning into a heavy period with awful cramps. My temp dipped two days ago. Could this be implantation bleeding this late & two days after my temp dip? Idk what to think anymore, all tests have been negative but idk how long after implantation it takes to turn positive.

I'll stop rambling now 😜