need some opinions

Some number just texted my boyfriend and he got "pissed off" because he doesn't know who it is, right? Okay, so I tired to call the number off of my phone and they ignore my call and when he texted them and asked who it was they said "nah don't worry about it wrong number "
I just have an odd stinking feeling that it's a female and that he does know who it is. 
Am I tripping ? We've been together 8months no problems like this ever ...