I'm 2 wks late.. should I buy a different test?

I've been taking cheapies for the last 2 wks. And I get a faint here and there, but not really distinctive, and its not getting darker. It's hard to read and my eyesight isn't the best. But, my question is, should I buy a different test and take it tomorrow? I've attached my cheapie test that I saw the faint line on.