How early was anyone able to see a pregnancy on scan ?

Jessica • Mummy to a 5 year old💙and 5 angel babies👣 Second baby born 28.10.20💙 Baby no.3 due 26th March 2023

Should have been six week but only 5 and only sac was seen? I had a blighted ovum 4 months ago my hormone levels are doubling very well this time so I’m praying