Sorry for the tmi but is this normal?

I’m 22 weeks pregnant and when I go to the bathroom 1 or 2 or even just sit my Libia majora swells up and gets firm. But only when I’m in the sitting position. It’s not hard or hurting just firm and the muscles I assume just harden/ flex. But it is about 2-3x the normal size until I sit or “push” to go to the bathroom. Is this unusual or bad for the baby? Is it normal?