Boyfriend and girl claiming to have had his child..

So this girl is claiming to have had a baby by my boyfriend. Well she's been texting me due to his phone being broken about the baby . Well we didn't tell her it was fixed until recently when he had to go pick up the baby. Well ever since she's known he has had his phone fixed she's been blowing it up with text and snapchats (nothing related about the baby when she talks to him). He told me that yesterday she sent a snap with her cleavage hanging out. I've read the text and every time she brings up she wants to do something he dodges it by telling her what he is gonna do with me. Do you think I'm over reacting or does it sound like she's trying to be a home wrecker? And should I say something to her about it?