Hello and welcome! 'Potting Compost' is a pretty generic term... there are lots of different kinds, and the brand you bought may be more water-retentive than you like. But if you've had more rain than usual, you might want to wait before repotting them with added perlite just yet; what's soggy in a wet spring may be perfect in a drier summer. Unless your plants are suffering. What kind of plants do you have?

Thank you for your reply. Since I live in a foreign country, and usually buy my planting stuff on the economy, I can't read the bags! Well, anyway, I have six roses, a hydrangea, Rhododendron, English lavender, summer Jasmin, Geraniums, impatiens, lemon thyme, heliotropium, Nemisia, Diascia, Dahlias, Lithodoras, fuschia, and mini petunias. My plants aren't suffering right now, and I wasn't planting last summer, but started in the fall with some fall plants, and the fall was fairly dry here. It should dry up a little here in the next few weeks, so for now I don't have to water anything outside. :) I still check on my plants though. I am currently trying to find a nursery in my area that has dwarf lilacs, which are my favorite, and am thinking about a few more hydrangeas, a white and pink to go with my blue.