Q. My roses are blooming but I haven't pruned them yet. Is it too late to prune them now?
The conventional wisdom is to prune roses in late winter or early spring, but you already know this. However, according to Rodale's pruning guide, you may approach this as a "maintenance" project. The method that is recommended here is to prune the older canes and leave the vigorous younger canes, which would result in the least amount of loss of bloom. If you feel that you need to prune the younger canes to shape the plant, you could cut them back, but, of course, you would lose a bit of blooming this year.
I strongly recommend that you contact the Philadelphia Rose Society for expert advice. Ed McFarland, a Consulting Rosarian for the Montgomery County area might be able to help you. He may be reached at 215-576-1436. You may tell him that a PHS Ask-A-Gardener volunteer recommended that you get in touch with him.
Wishing you a glorious season of blooming roses.