Spotting/Bleeding

Im 8 weeks 4 days pregnant today and experiencing spotting since Oct 29 until now pero yung last check up and transV ko normal naman at may heartbeat na si baby sabi ni OB ko baka sa implantation bleeding parin ang cause ng spotting. pero im still worried at di maiwasan mag isip. second pregnancy ko na tu, my first is blighted ovum. sino po nakakaranas ng same case?