My friend has madeworried about pregnancy test?

Hi! well I took 3 pregnancy tests the past week and all came up positive. they were clear blue. I'm really excited about being pregnant but when I told one of my friends (she has never been pregnant before) she said just because 3 pregnacy tests says that I'm pregnant doesn't mean that I am. What is the persentage that 3 could be wrong? should I not worry about it? I have symptoms even: a lighter period and it was oober late. Increased apitite, going to the rest room every two minuates, and felling ill in the morning. Im really worried about what she said cause both me and the father are really excited. I have an doc appt. monday but still worried if that test will come out negative. SHould I worry?( srry just asked that) Input would be very apriciated and thank you soo much for your responses