Top front two crowns move slightly if I touch them with my finger. Is this normal?

Teeth naturally move due to position, bite and if a patient clenches or grinds. You may want to have your dental provider take X-rays to confirm the crowns are seated completed and that there is no gap between the crown and the tooth. Also, your dental provider can confirm that there is no infection present around the tooth on the X-ray, since that can make teeth somewhat mobile. If everything appears healthy, there still may be some movement due to your bite, position of teeth of if you are a grinder or clenchers. If it is your bite then it would be suggested to adjust the bite. If you are a grinder or clencher, then it would bar suggested to get an occlusal or night guard. 

Sometimes if the crowns are a little high (they touch the opposing teeth before the rest of the teeth touch) it can cause those crowns to move with the teeth. There is also a possibility that the crowns may be loose and the cement did not hold well. Teeth naturally move if pressure is placed on them so it depends on how hard you are pushing on them. The best thing to do is return to your dentist and let him/her take a look.