Science shows that astrology is nonsense.
Here is a meta-horoscope created by combining 22,000 star sign predictions.
http://www.informationisbeautiful.net/visualizations/horoscoped/
Notice how all the different star signs are nearly identical and vague.
Also, the alignment between Earth and the star constellations has changed since the ideas of astrology were originally made up, so your 'sign' is no longer the one it should be.
I would recommend checking out Phil Plait's blog as he often talks about this topic, the following is from his site:
"...the signs of the zodiac have shifted since they were first invented thousands of years ago. This is true, because the Earth’s axis wobbles over time, which has the effect of shifting the positions of the zodiacal constellations in the sky, or, more accurately, the time of the year the Sun passes through them. So it used to be that if you were born on March 22, you were an Aries… if you went by the original timing of when the Sun was in Aries. But now, millennia later, the Sun is actually in Pisces on that date. And it won’t be much longer before it’s in Aquarius in late March"
http://blogs.discovermagazine.com/badastronomy/2011/01/13/astrological-sign-of-the-times/