Very thin, faint line am I pregnant?

My husband (in a rush to get out of the store) purchased a few boxes of the RITE AID brand early detection pregnancy test. It says the test is comparable to First Response. I have taken 3 over the last 24 hours; one yesterday evening, one last night, and another this evening. Each time, I get a very thin, faint blue line. Its about the size of a single hair. At first I thought I was just seeing something, but as time ped, the test got darker and darker, now I can clearly see a dark thin blue line on all of them. Its not a clear evaporation line, but a very distinct light blue one. I'm going to take one more in the morning, and I have an appt. for a blood test tomorrow. Do the lines sound like a positive test?