The undies I wore today felt a bit tighter than usual and I got a bit bruised up on my inner-most thigh. I was sitting down a lot at work and then at a restaurant. Maybe you have experienced something similar. It could just be your knickers.
Oh and also because your labia enlarges during pregnancy AND your trousers all get tighter, you tend to lose that extra roomy groin space in jeans and work trousers. The inner seam of your trousers probably bruised your labia by rubbing against it all day.
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