Continues crashing every time I attempt to log in.

I log in. All perfect. So far, there are no issues or bugs to report. I am on the Mojang loading screen when, suddenly, boom! Minecraft stops responding and after a wait of roughly 3 minutes, it takes me to the 'crash report' tab of the opening programme.
I hope you can do what ever you now do and get back to me soon.
Thanks.