Ate, I can really feel how worried and confused you are right now, and that's completely valid, pero ang best thing you can do talaga is get a clear second opinion from another trusted OB as soon as you can, especially since your three scans showed different findings. Hindi ko alam kung ano talaga ang nangyayari sa baby mo, pero yung inconsistency ng results mo (6 weeks vs 12 weeks dating, that low heartbeat, different clinics) ay kailangan talaga i-clarify ng isang experienced doctor, hindi ng friends online. You deserve certainty, hindi assumptions. A few mums I know din nag-struggle with confusing ultrasound readings, and grabe ang peace of mind when they finally got a clear professional answer, kaya please book that appointment soon. Wishing you strength, mama.