So the hospital gave me two pills last night that where pencillin vk now that i got my persrcption filled they don't look the same can i be allergic?

Different brands: There are different brands of generic medications so the ER might have one particular brand and the pharmacy another. The medication will be exactly the same as approved by the FDA. Check with the pharmacist if you want to be absolutely sure that you were dispensed the correct medication.

Different brands: or products made by different manufacturers might look different and still contain the same medicine. If there is a question, call the pharmacy and ask them to look in their penicillin supply to be sure it looks like your medicine. For penicillin, there is a distinctive smell you may notice with almost any manufacturer. You will probably even smell it in your urine - this is normal.