L.L.
Not unusual at all J.. While there is a usual pattern for the emergence of teeth (i.e bottom central incisors first, then top central incisors) it is not uncommon to stray from this pattern. My own daughter had 3 molars come in before her top lateral incisors came in and when I asked the dentist and pediatrician about it, they were not concerned at all. As long as the teeth are coming in, you don't have to be worried.