Congratulations sa second baby, mama! With PCOS it can take a bit longer for the gestational sac to show up on ultrasound, so ang spotting na ganyan mixed with mucus ay common especially pag very early pa, pero kasi inconsistent at may PT positive ka, kailangan mo talaga i-follow up with your OB para ma-monitor properly, baka kailangan repeat ultrasound or HCG levels to make sure everything's progressing okay, kaya better safe than sorry talaga.