FRER staying the same but clear blue digital went from 1-2 to 2-3

Kay
So I got my BFP on 12/31/15....I got a 1-2 pregnant on digital. I tested with FRER and saw two lines, but the test line was light. 
I retested two days later and the line was still faint. 
I tested again this morning (because I'm mildly addicted) and got a 2-3 on the clear blue digital, but the FRER line was just as light as the very first test I took! 
Should I be concerned?!?