Yelp is a community where the more you post the more credibility you gain and your reviews are filtered less and less. Only 1 person of the many filtered reviews has more than 10 posts.
That said you do have a 3 star average (which is "A-Okay") and many other good restaurants have the same. The good news is that since you're new, as you continue to get better with whatever growing pains you encountered out of the gates that drew disappointment, then surely more of the 4 star reviews will come and you'll be a 3.5 average and beyond. Its once you slip below 3 stars you really should worry.