Question: how many days post ovulation bfp?
Answer: They're miscalculating when they ovulated. This is most likely the case for anyone who claims to get a positive test at 7 DPO or earlier. It can take up to two days for hCG to build up to detectable levels, but it can happen sooner for some women. This could explain positive pregnancy tests as early as 8 – 10 DPO.