What did you use to make the bootable USB? It sounds like it did not write properly (this happens occasionally). Just rewrite the USB. At present time UNetBootIn does not work with Antergos ISOs. The easiest method to use is dd from command line. Not sure on your experience level so here is a step by step.
1. Navigate to the directory that you saved the ISO using Files (Nautilus)
2. Right click on the ISO file and click copy.
3. Right-Click anywhere in the white space (Not directly on file) then click "Open in Terminal"
4. Input (without quotes) “sudo dd if=” Now press CTL+SHIFT+V to paste the ISO that you copied and delete “file://” from beginning.
5. Input “of=/dev/sdb” (Where sdb is your USB device name, if you only have the one device plugged in then it will be sdb)
6. Hit enter and let it copy! You will not see any status update until it completes, only a flashing cursor. Be patient
Here is the complete command:
sudo dd if=/path/to/file.iso of=/dev/sdb