How early was anyone able to detect 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

I should have been six weeks but only measured 5 only a sac was seen scan on Friday to see if anything progresses but my hormone levels are high! I suffered a blighted ovum 4 months ago so very worried x