This is a normal part of growing up. Children will fixate on certain things, such as a blanket or a pacifier. They may even have set patterns of saying goodnight or giving hugs and kisses. All of this is normal. It becomes a problem when a violation occurs and they are unable to handle the change in their routine. This still may not be OCD, but it may require you to do some exposures to help your child adjust to differences in routines and to get him or her to accept that changes happen. If there are still difficulties, then consulting with a behavioral therapist may be necessary to help you come up with exercises to help your child adjust to new routines or occurrences.