What the hell?! TMI

Ok so I have a pimple like bump on my labia and I have noooo idea what it is. I've never had an std and my SO had only done sexual things with me. I've had something similar before and either I popped it or it popped on its own. It's not itchy at all. When I squeeze it it feels like there's a bead on it. Any clue what this is?!?!