Before you go the route of the labels and considering that a small child has something like anxiety it would be good to find out if it is as simple as missing his Mom which is pretty normal, the problem is if you go the ocd anxiety ADD route he will end up on the powerful meds ,check out the ADD and the ADHD forum, when you dont looking for extreme problems when most times it is 'normal behavior,I do not beleive that any child whyo runs around or cries has some problem that requires tests exams and eventually strong drugs, however it is always best to ask your Doctor first .
Yes, it is possible that your child suffers from anxiety. Anxiety is an inherited trait and we saw evidence of anxiety behaviours in our child at four hours of age (of course, at the time, we did not realize what we were seeing). I might suggest you google the phrase "toddlers and anxiety" to read more about this issue. OCD is one of the anxiety disorders so whether or not OCD is the issue with your son is irrelevant. If anxiety is the issue, it can be very easy to treat at two years of age - often just patience, understanding and some intervention practices. If you suspect anxiety, it might be wise to discuss this issue with your child's pediatrician. Hope this helps ....
The only thing wrong here in my opinion is that he is missing you I doubt if he has ocd, some children are just not ready to be placed in day care away from their Mom, is there any way you can cut back hours if not then you just reasure him he misses you .It is obviously having an effect at home aslo. If you are concerned take him to see the Doctor and get him checked out.