Aw mama, totally normal yan especially during pregnancy, a lot of us go through that, and one of my mum friends said ang hormones talaga plus the anxiety of bringing a new life into the world kaya mind goes to dark places. But if these thoughts are really taking over your day and making it hard to function, I'd really encourage you to talk to your OB about it, kasi may support available whether it's counseling or kung kailangan ng intervention. You're not alone sa feeling na ito, at it's actually a sign na you care so much about your baby na!