Well, if you are shaving your nether-regions, you can certainly get an ingrown hair...
Since you refer to it as looking like a "pimple" I wouldn't worry overmuch about it, but if it is a LUMP, then go to the doctor because you have lymph nodes in the region that can get cysts on them that may need to be lanced.
A warm compress/bath may help, but I would recommend you defer your personal landscaping routine at the present time while it resolves or you receive treatment.