During my last crawl suddenly no errors or warnings were found, only one, a 403 error on my homepage.

[KnowHowww]

There were no changes made and all my old errors dissapeard, i think something went wrong. Is it possible to start another crawl earlyer then scheduled?

[FedeEinhorn]

No that I know of. Just wait for the next crawl. They do one weekly so you shouldn't worry too much about it.