Is my boyfriend ignoring me?

Lately it seems like I'm the first one to text him and when I do, it takes at least an hour to text back. He lives a half hour away. When I asked him to come over Wednesday, he said he already had plans to hang out with his friend (who is a girl). I asked him the next day and he said he had to help his aunt with something and we didn't talk all day. I'm starting to get really mad and a little sad because it never used to be like this. The next time I'll be able to see him is Tuesday. When I went on Facebook today, I saw pictures of a girl that I've never seen on his profile that were taken yesterday when he was supposed to be with his aunt. I don't want to freak out (most of his friends are girls) but I don't know how to deal with it. Is there something he's not telling me? What should I do?