They do that when conditions are right.some gardeners will pinch them off, sometimes they fall off on their own. Since romas are determinate, you could pinch off the flowers. However, the plant will continue to grow as fruit developes, you are an easy 30 days away from fruit readiness and by that time your plants will be big and strong enough to hold fruit.

To me that plant is not too young or too small to flower. It will take about 50 days for the flower to become a ripe fruit. And in the meantime the plant will also grow in size too. Tomato plant can allocate its resources to wherever and whatever needed. If it could not support the fruit, plant will abort it itself.