From the Sooner Plant Farm, here is some information on this cultivar, which is a cross between Ohio native Campsis radicans (Trumpet creeper) and Campsis grandiflora, which is native to China and Japan. Since Campsis grandiflora will not appear in our Native Plant Database and we have no idea what effect the hybridization would have on the resulting plant, we will just make a couple of educated guesses.
If you follow the plant link Campsis radicans (Trumpet creeper) to our webpage on this plant it will help understand what growing needs the native has, at least. According to that page it needs full sun (6 or more hours a day of sunlight) to bloom well, and has red, orange or yellow flowers from June to September. It is possible that in your cooler hardiness zone, they may not start blooming until later in the summer. Another possibility is that the plant you purchased in the nursery had blooms that had been forced for better sales, and the plant is not yet quite mature enough to bloom normally. A third possibility is that the plant is being fertilized too heavily, especially with high nitrogen fertilizers. These are intended for grass, and stimulate green leaf growth. An over-supply of nitrogen can inhibit blooming. And,in fact, most native plants need little or no fertilizing, but since your plant is not totally native, we couldn't be sure about that.
Please also note that the Trumpet Creepers are all etremely aggressive and can become invasive. Don't let it get away from you, keep it clipped and trimmed and in check, or you'll have vines coming in your bedroom window.
Pictures of Campsis grandiflora