What if the back line is faint......

So I took another P test after getting 2 positives one a couple weeks ago. Because I had one left and figured why not. It came out looking like this. The back line is very faint (can't really see in picture) while the 1st line is red which according to test the front line should show when pregnant. My 1st 2 tests had very strong lines, this one is faint. Does it mean anything? This will be my 3rd pregnancy; I should be around 6 wks.