start-up cycle

Question
I have had my 20 gal. tank for about 1 mo. and 1 week. I let my tank run for 1 week before adding any fish. I added my fish(4 of them 2 mollie and 2 gourami)about a month ago. I test my water regularly and I have noticed that the ammonia and nitrites spiked up, but now the ammonia is at 0 and now the nitrites are at about 10 and nitrates are at about 40. The nitrates and nitrites have remained the same for almost 1 1/2 weeks now. I have done some small water changes but I would like to know is it normal for nitrates to be elevated and nitrites to be really high at the same time with no ammonia present? And if so what should I do, if anything? I don't know if I should keep doing small water changes or not.

Answer
running for one week is when you put starter fish for the tank to cycle, and youre not supposed to put in fish for after cycling. cycling fish are platys and danios. It sounds like your tank is almost done cycling since the ammonia is down and nitrite/nitrate are way up. These are lethal to fish like ammonia and you need to do alot of water changes.