Its definitely a good idea to communicate this with your provider.. I really cant imagine any lady having an issue with working with you on this.
Like others said, bringing and wanting to use your own can be a concern for some ladies, not just the tampering factor, but also because she may have sensitivities.
Im really sensitive to the lubricant used in some condoms...I got it narrowed down to that, but Im not sure what it is..since even within the same brand, certain types are no prob and others..major prob! So Im always apprehensive about using a condom that Im not already familiar with. The wrong one could put me out of commission for a week or so.