Crazy ex girlfriend???

Hi guys! So my current boyfriend and I have been together for 2 years now and... yup. We’re still dealing with his ex girlfriend! This girl has tried to start shit with me about a year ago, about 2 times, and continues to call my boyfriend on different numbers because he keeps blocking her number.

Just now, she messaged me once again on Instagram trying to tell me that my boyfriend is messaging her? I don’t know what to believe because she has screenshots but they look a little fake too. I talked to my boyfriend and he swore hes never messaged her and offered me to even look at his phone. He’s never done anything to make me not trust him and I honestly don’t know what to do about his ex??? Any suggestions??