Thousands of flag-waving, whistle-blowing, merengue-loving revelers filled Sixth Avenue yesterday for a Dominican Day Parade filled with pride and pomp. Paradegoers thronged to the Midtown streets with music and colorful attire in an all-out celebration of Domini can culture. “I love this parade,” said Julio Veras, 32, decked out in an “I ò DR” T- shirt. Beside him, his son Ivan, 5, wore a Do minican flag on his back like a superhero’s cape. “It’s a celebration of our culture, our history and our pride as Dominicans,” Veras said.” Amy Sanchez, 22, of The Bronx, said, “This is our day to represent, baby.”