WP-Admin troubles won't log in just refreshes

I’m not sure what to do. For a week, my blog admin won’t let me log in! I enter in my username and password click “enter” and it just goes to a black page. No error message, no nothing. Just nothing! It’s done this before maybe for an hour or something but it’s been like this for 6 days now! It’s also not a host error because my blog (jamiedelaineblog.com) actually works still.