No heartbeat

Kahapon 8/15/19 after work around 7pm cr muna ako bago umuwi. Pag baba ko ng underwear may kunting dugo. Sobrang kinabahan ako. Kaninang umaga 8/16/19 around 8am nag cr ako meron ulit pero mas kunti kesa kahapon. Nagpa TVS ulit ako kanena for the second time (unang tvs ko I was 6 weeks pregnant no heartbeat seen at bumalik nalang daw ako after 2 weeks). Now Im 9 weeks & 1 day pregnant. OB said wala siyang makitang heartbeat??????? bakit po kaya????