Is she losing interest or has she found someone else?

So I have been seeing my girlfriend for 9 months. We are both in our late 20s and live in different cities but see each other a few times a week and all is great when we are together. Lately though she has gone completely silent, and I always have to call or text her first. This was not the case before as she would blow up my phone but now she doesn't even send a good morning message. When we do talk on the phone she seems fine but why this silence all of a sudden?
Is she losing interest or has she found someone else?
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