I bought these and they taste great. A Mexican buddy of mine at school let me have one and I was hooked. The only problem I had with these is that is was the Aldama brand and not Las Sevillanas but it is still a great tasting Oblea with cajeta and I plan to buy again.
The hook effect and false BFNs. Summarised, the hook effect is when someone continuously gets negative urine and blood tests but are actually pregnant. It happens because hcg levels are too high to register and is common with mothers carrying multiples or on older woman.
Some assays may include an antibody that does not recognize certain variants present in later stages of pregnancy. When this variant is in excess, it can bind one antibody avidly and the other not at all, resulting in a false-negative test (hook-like phenomenon). In both situations, dilution is key to an accurate test. Conclusions: Manufacturers should consider that uhCG tests are routinely used at many stages of pregnancy.