We don't recommend wearing a thong because it could be more difficult collecting a good sample. Full-coverage underwear is our recommendation for a smooth collection process- it will help kep your Q-Pad in place and avoid leaks.
We understand this can be an inconvenience, but the great part about using a Q-Pad kit is that you do not need to wear the pads for the entire duration of your period. Each kit comes with two menstrual pads that are typically worn for 2-4 hours, depending on your flow.