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I can very well understand your concern, but a day after the expiry date would not do any difference. Expiry date would not make the drug ineffective right away. Rather what it means is that the the drug after the expiry date will gradually (remember gradually not suddenly) will start losing its potency and efficacy over time but a difference of one day should not make any difference at all. It's actually the cut off limit mentioned by the pharmaceutical companies for a variety of reasons best known to them.
I also do somewhat agree to what Dr Gregory Khan has written that April 17 could be that the drug expires in 2017 because of the reason that different countries have differences in the way units are measured.
So I would recommend you to take the medicine packet/strip and consult your doctor even if the drug is expected to expire in 2017. Or you can also let us know where did you purchase the medicine and how exactly is the date of expiry mentioned on it.
This would help relieve your anxiety
and help you concentrate better on your priorities.
Thanks and hope this helps