Your comment that he wouldn't let you call the police bothers me immensely. The only reason I can think of that he wouldn't want to notify the police is if he is engaged in illegal activity (and that could be the reason for the attempted break-in).
Call them NOW; if he is involved with anything illegal, you do NOT want to become an accessory after the fact.
Call them NOW; if he is involved with anything illegal, you do NOT want to become an accessory after the fact.