Need advice please

Okay so I was suppose to start on the 27th of may!!! I still haven't started that's nearly 2 weeks late. I took a test and it showed a faint positive with blue dye:)! I took another test with a pink dye it showed negative.:( so the past three days I've been getting really bad dizzy... well I went to the error last night over it and they did a pregnancy test and it showed negative.. If I go back from last period I would be about 5 weeks 2 days pregnant. With my first born I didn't find out till I was nearly 7 weeks 6 days pregnant! Could someone please explain to me what they think is going on! Praying for baby dust here I want another baby so bad...... :((