I assume the recipe was for refrigerator pickles, in which case no seal is expected. You CAN still do a water bath but the additional heat will result in mushy pickles.
I have made batches of refrigerator pickles with a recipe that calls for pouring a boiling brine into a jar containing raw cucumber, garlic, onion, and dill. When I've used boiling water to sterilize the jars right beforehand, most often they have vacuum-sealed as they cooled. Even using assorted jars from mayo and other condiments, where no vacuum forms, as long as I have boiled the jars and lids I have had success in storing the pickles at room temp.
Just to clarify: your recipe said that you didn't need to use a water bath to process? Were they meant to be shelf-stable, or fridge pickles?
Testing for a seal is easy - if the center of the lid is up, they're not sealed. Technically, if you touch the center and it pops down, it's sealed, but I am always concerned about jars that I need to 'help' seal, unless I'm doing jam.
How long has it been since you made the pickles? Can you post more info - recipe, exactly what you did, etc?