Doubting my pregnancy

This is my first pregnancy. I am estimating I am about 8 weeks pregnant. Doctor will see me for first appt. on April 20th. Every few days, I really start doubting that I'm really even pregnant. I've taken two positive tests and have had very, very slight symptoms (little nausea, tender breasts and fatigue), but I still have these doubts like maybe I'm not and I'm making this all up. Do you think it will become more real once I go to doc and actually see the baby? I almost want to go take another test or two to make sure this is real.