Thanks for the query.
Usually some amount of rugosity can be seen near the vagina.
The labia minora
which will be covering the vaginal opening can show rugosity due to containing thick layers of the tissue.
So when you pull the tissue, these rugosities can become prominent and can appear as bumps.
If you do not have any symptoms like white discharge, itching etc, no need to worry.
As you got tested for STDs, there is less possibility for any infection.
For more details you can ask me directly through the premium forum.