Why are my teeth so stained?!?

Okay, so this saturday i'm going out with a guy and need to get my teeth super white. Most of the time during summer i'm rushing to get in bed cause i'm exhausted so i just wash my face with acne cleanser and brush my teeth with a Reach toothbrush (forgot the brand, sorry). Throughout the school year i would use Listerine Whitening (the before rinse) and my teeth would come out really white. So now, where i'm going out saturday, i've been giving my teeth at least a good 12 minutes before jumping into and right after i get out of bed. I use Listerine Whitening Rinse, brush my teeth with my Reach brush (that also has whitening) and use Crest Extra Whitening toothpaste, and then use Crest Whitening Rinse (for the after) and it still doesn't come out white (and i've been keeping this up for a week, so i should've already seen some improvement. That's the way it always is during the school year)! I never drink coffee and the only type of soda i usually drink is Mountain Dew. I've also been drinking a lot of lemonade lately, could that be a problem? How can i get them white again? Thanks xoxo