Need advice

I have a friend who is very sexually active but some of her decisions about how she does it I don’t agree with. Me trying to be a good friend you know I share all my knowledge that i know about sex with her. For one she’s having unprotected sex with multiple people😐 and she’s not using birth control😐 those are 2 red flags 🚩🚩😴 SO witch that being said she recently missed her period for a month but then it came the next month. I told her that she should get a check up to make sure she’s not pregnant. But since it came the month after she still refuse to go to the doctor😐😐😐 I’m not bashing her on how she get hers it’s just when you miss your period cause she MISSED the whole period for a month. If it comes the next month that’s doesn’t necessarily means you in the clear does it??🤔 now tell me if I’m wrong I’m open to all opinions