Abscess / boil groin area

La

This is so gross / embarrassing but I have an abscess or boil under my butt cheek/ near my vagina that is so painful. It’s probably the size of a nickel and feels like chafing or something. Would my OB look at it and lance it? Or is this something I have to go to the ER for? I’m lost and grossed out. As if being 34 weeks pregnant isn’t enough stress ha.