Are you carrying drugs or other contraband? No? Then you have nothing to worry about.
Are you carrying 10,000 rounds of ammo? No? Then you have nothing to worry about.
Are you here legally? Yes? Then you have nothing to worry about.
I routinely (EVERY WEEKEND) go through the BP checkpoint east of San Diego, towing a trailer with a truck with a shell. Alone. In all the years I've been doing this, I've never spent more than a minute stopped behind traffic, never been searched, never been pulled into secondary. I actively engage the officer in conversation, thank him/her for their service, and go on my way.
Do I carry weapons in my trailer? Yes! Loaded? Yes! I even have (gasp!) alcohol in my trailer!