So I’m 7 days late and I took a pregnancy test last night. And there is the most faint positive line. Should I take another test right away or should I wait a few days?

So I have gone to the doctors....I have all the symptoms of early pregnancy but a negative urine test. In the morning I’ll be getting a blood test, if I got pregnant when I think I did I would only be 3/4 weeks pregnant. Could this be too early to tell if I am or not?!