No worries. If they are small flies, they are probably pollinating the flowers to make more produce. If large flies are attracted, then perhaps you have some overripe or rotting tomatoes and peppers. Keep the area clean of diseased and rotting fruit. Manure can also attract flies, so if you used manure bury it under the topsoil or top it with a mulch of wood chips. Keep growing, Marianne Binetti