What is your opinion on a guy who starts ignoring his girlfriend?

[CountryGirl]

I was seeing this guy for a bout 3 weeks everything was going great! It seemed like he really really liked me than out of nowhere he started saying that he was really busy at work and he wouldn't be able to talk to me then the same thing the next night. To where it got to the was only sending me a message through facebook once a day and when I said hey what's up with you he totally cut off all communication with me. I honestly don't know what happened and would like someone else's opinion on the situation. Thanks!