Best friend seems off

So me and my best friend who is long distance seems kinda off. We use to talk a lot about random things. All of a sudden now she doesnt talk to me much anymore. I have to start a conversation and try to keep it going or else she leaves me on read. Most the time when i say anything trying to get a conversation going she leaves me on read. I want to ask her if everything is alright but i dont want to seem like im pushing it or i may just be overthinking it. But i asked her how shes doing and she said shes good but i dont really believe her. Im just worried.