While it's possible that your birth control changed packaging, it's more likely that you received a generic version of your medication.
We understand your confusion with receiving something that appears to be different than what you were expecting, but it is the same medication. In order for a generic substitution to be made it must be proven to the FDA to be the same thing. The product received has the same active ingredient, dosage form, strength, route of administration and conditions of use as the requested drug, and the received drug product is bioequivalent. It would be equally efficacious. You would not experience any difference between the two as they have proven they are the same thing to the FDA.