Are teeth whitening bad for my enamel?

Hello all!!
I'm working in an MNC. Day by day I'm engaging with different platforms and new techniques based on my job. I used to take almost 5 cups of coffee per day. As I became a coffee addict after joining in that company my teeth seem to be yellowish. Every time I used to think of taking a half day leave and to get any cosmetic dentistry services ( http://www.ottawadentaloffices.ca/cosmeticdentistry/ ) for my stained teeth. But the problem is my daily schedules and meetings always make me cancel the dental appointments. Next week is my birthday. I'm damn sure that there would be some surprises for me. My bf is busy with his plans which he is trying to make secret. But I know his plans very well. I'm planning to wear his favourite dress on my special day. But the problem is with my yellow teeth. How will be able to pose for selfies with this yellowish teeth? I need the teeth whitening procedure to be done before my birthday. I have taken the appointment at a nearby clinic in Ottawa without bothering my meetings. I'm doubtful whether how long does the teeth whitening last? And will it affect my fillings, veneers or crowns? What is your opinion?