I would talk to your dr. I'm not sure about the patch, but I have read that taking the pill while pregnant (before you know you're pregnant) is not harmful to the baby. Do not stop your birth control because what you are experiencing could be from starting and then stopping the pill and then starting the patch. You may or may not be pregnant, and stopping the birth control is only going to throw off your body if you are not pregnant.
i believe that u have to be at least 2 weeks pregnant before a test can read positive but i am not sure, however, if you believe your pregnant you should definitely stop using contraceptives.