Implementation bleeding or Aunt Flo

So I o-ed on the 9th and figured Aunt Flo would be here on Saturday (24th). I started taking pregnancy tests on Tuesday, Wednesday and today - all bfn. Yesterday I noticed a tiny brown spot on my panty then had a brownish discharge when I wiped last night. All day I have had tiny spots of pink when I wipe. Nothing much and so light, nothing red. Af really isn't expected for a few days so it could just be pre-af. But I would be 11-12 dpo yesterday and today so seems as though there is a slight chance of implementation bleeding. I know there is no way to know for another few days to see if the Flo comes on and if I see a bfp. But the waiting is Torture!
Bit of background, I have a healthy 2 year old. Am trying for number two. Started trying a year ago, finally got pregnant in July. We miscarried in September. Waited a cycle tried again and had a chemical pregnancy in December. 
Fx on this one! If af comes - we wil try again!