Just Advice

I’m going to speak with my manager and her manager today due to me being pregnant and my safety at work. But I would like advice on whether or not I should bring something up to my boss’s manager. One of my coworkers is constantly calling in other workers to cover the end of his shift. It’s never for emergency reasons. One of the times it was even for a party. But he seems to do this every single week and it doesn’t seem like my boss cares about it. One of my coworkers always says yes to come in because she feels obligated. The other says yes because she’s apart of his clique and covers for him. I would have gone to my boss but she has chosen to ignore me and that’s why we’re going to this meeting today. I would obviously ask if I could speak to her boss alone and tell her. What should I do?