Yes, it could be allergy but it need not be. Many skin diseases may present in this fashion, that is as an inflammatory “patch”. The main question to be answered is whether this is or is not infection. If it is not, then all that may be required is the application of a topical steroid. However if these patches are infection, antimicrobial therapy would be appropriate.
Given the time constraint of your wedding and the need to look your best, I suggest that you seek assistance from a Dermatology specialist.