Its hard to say, it could be either. The important thing is whether you have concerns. If you do go to your GP and explain your concerns and ask for a referral to a Paed.
For what its worth ds at 3
Wasnt potty trained (but 3 is still young)
Loved numbers too and anything with a pattern, such as jigsaw etc.
Liked things to be order, in his order and he always had to be right
Always lined things up, cars, sweets etc
Sometimes was shy and would hide
Other times could talk for England and hug strangers, but only about things that interest him
He had and still has a brilliant imagination, he can pretend and role play, but he has great difficulty including the ideas of others into his play. Although he will let others join in, he will then just let them take over, without adding any ideas of his own.
He also had other difficulties such as delayed speech, extremely limited diet etc.