I planted 3 tomato plants approximately late May to early June. Two have tomatoes on (1 on each) but the one does not have anything yet. The plant itself appears very healthy and rich and my husband wants me to relocate it. I say give it a little more time.
Certified GKH Gardening Expert
You may have to much Nitrogen in the soil.
You can use Bone Meal to raise the Phosphorous in the soil.
Here are a few links for you.