I've been feeling nauseas since 20 days...I don't puke but every other time I feel like I have to?

Get going. Your symptoms may be serious. Common and treatable problems include stomach ulcer disease problems with liver, kidney, and infections could be present. If you are dizzy, lightheaded, or weak, in addition to the nausea, seek help immediately.
Get examined for. Stomach and esophageal irritation and have a thorough exam and blood work to rule out other medical conditions. Take care!