cross a bridge before one comes to it
cross a/that bridge before (one) comes to it
To be very concerned or make a decision about something that has not happened yet. Thanks to my anxiety, I often to cross a bridge before I come to it. A: "What if I don't get the job?" B: "They haven't called you yet either way, so don't cross that bridge before you come to it."
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
cross a bridge before one comes to itand cross that bridge before one comes to it
Fig. to worry excessively about something before it happens. (Note the variations in the examples. See also cross that bridge when one comes to it.) There is no sense in crossing that bridge before you come to it. She's always crossing bridges before coming to them. She needs to learn to relax.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.