I don’t know where else to ask this question.. I am exclusively breastfeeding my 3 month old. I got my period back at 6 weeks pp, I logged it into my Glow tracker and then my next period came exactly as they predicted, and now I’m on cycle day 18 and should be ovulating- I have been having a decent amount of really dark brown discharge- enough to change a panty liner every time I pee. What could this be? Old blood- from what? Ovulation spotting? Husband is away for work so have not had sex recently.