Caller ID spoofing. That would explain both incidents. No need to have access to your phone. No need for you to change your number, etc. A greater concern is that it looks like you have a serious psycho in your social circle who needs to be dealt with.
What happened with my cell phone Saturday night? - cellphone hacked | Ask MetaFilter
For the past 5 years, the year teaching veteran has worked to transition his ninth-grade World History and AP Government classrooms into a mobile device-friendly environment where students can incorporate the latest technology into the learning process. Ken Halla with students. And with over 50 percent of mobile phone users in America now using smartphones, the numbers only seems to be growing. Ensuring it stays academic Many teachers have a zero-tolerance policy when it comes to phones out during class, since they assume—most of the time correctly—that their students are using them to text friends or update their various social media sites.
Students will demonstrate academic competence, with particular emphasis on language arts and mathematics literacy. Students will demonstrate effective English communication, critical thinking, research and technology skills. Students will demonstrate personal responsibility, tolerance for individual differences and participation in school and community life.