Pain during masturbation

Recently I’ve been noticing pain when I’m fingering myself and when my boyfriend is as well. It seems to only hurt while laying down, and by the opening on the left side specifically. I have had sex since I’ve started feeling the pain, but it doesn’t seem to bother it, while fingering does. My boyfriend mentioned feeling something hard in there and it scared me, but I couldn’t find what he was talking about.. so I’m not sure what he was talking about. I gave myself a self exam and I don’t know what I’m doing despite research. I’m still under 18 and my mom loves inviting herself into the doctors office with me, so I am uncomfortable mentioning it. Do you think this is normal, or no? And any suggestions on the doctor situation?