Sudden penetration pain

I'm not a virgin. I've had sex before and pain isn't a thing that usually happens except maybe initial pain when I haven't had sex in a while. Recently I had my first Pap smear and said i looked completely healthy just I had asymptomatic BV. I took the antibiotics and done. Tonight I tried using a vibrator for penetration. I made myself orgasm before and used lube and when I inserted and used it I did not feel good. It hurt. I don't know why. What could be happening??