I change mine every 3 days and it's always been OK but I have heard on this forum of women who seem to absorb a lot of the oestrogen very quickly from the patch so levels drops off quicker. Maybe something to do with your skin, where you apply it and generaly body temeprature? Absorption will be higher if warmer and if skin is thinner I would say. Could you try changing application site and see if that helps and then increasing the dose as well if you feel absorption is much slower?
Hurdity x