Are these pregnancy warnings true

I’m a first time mom and I always have so many questions for my doctor but he is very old , he is good but he really doesn’t talk much or offer any information at times so I just sort of shut down and ask fellow moms around me. Being a new mom I’m going the extra mile trying to avoid anything that can harm my baby and I came across these posts. Fellow moms are there any truths to these in your experience and can you please explain? I’m so nervous about something going wrong I’m currently 4 months