Uy mama, kahit light lang yan, please go see your OB agad, 5 months postpartum at 3 weeks ng bleeding is something she really needs to check out, okay? Better safe than sorry, lalo na kung mixed feeding ka pa. Sabi ng few of my mum friends na nagkaroon ng similar situation, may ibang reasons pa puwede doon na kelangan ng proper check. Don't worry, doctors see this all the time, pero importante talaga na malaman kung ano talaga ang cause. Let us know how it goes, ha?