20 AMP Wiring issue

Brand new 20 AMP Breaker and 12/2 wire. Leaving the panel to a junction box with for out going lines. Two go to outlets, two go to other junction boxes. The other two Junction boxes feed two other outlets. After several days the breaker will trip. I have disconnected one outlet and the breaker stayed on for almost a month. Connected that outlet back up and breaker tripped in a week, then again the next day. Thought I was disconnecting same outlet, but by mistake disconnected the other. Breaker has stayed on. How to troubleshoot this?