Hi Ron,
No, the originals aren't saved anywhere by WavePad unless you saved them yourself. The only time WavePad will leave unsaved audio data on the hard drive is if it crashes or is force-quit, in which case WavePad will ask you whether to recover that data the next time it runs. I think your best hope is that you did save the original recordings somewhere (maybe as .wav?) before editing them and saving them again as .mp3.
I know it's probably too late for this, but a good principle for recording is never to do anything irreversible to your data. Some examples of this principle applied are:
1. Use a good microphone, in a quiet room (to start with the best quality data you can),
2. Use a reasonably high sampling rate (44100Hz or 48000Hz are good), since lower rates discard human-audible audio data,
3. Save to a lossless format (such as WAV, FLAC, etc.), not to MP3, which irreversibly reduces quality,
4. Keep original recordings in say an 'originals' folder, then save any edits to other folders, ie. 'originals-trimmed', 'originals-trimmed-noise-reduced'. I'm sure you've already learnt this one!
Best of luck,
Alex