Is this really a girl?

This entire pregnancy my gut said it was a boy. Even the heart rate at all appointments and everything said it was probably a boy. Yesterday at my 20 week ultrasound the tech showed me the babys legs image, and I could swear I saw something long sticking between the legs. Then she moved the probe and within a second said "oh look I see 3 lines it's a girl." I was shocked! She spent a few seconds writing it's a girl and moved the probe away.

I don't know why in my gut I feel there is a chance she was wrong. I do see the lines in the image, I actually see 4 lines, but regardless I don't know why I feel this way.