Fishless cycling does not always require liquid ammonia, but any type of cycling takes much more than three days, however, there is no set time limit on when a cycle will begin or be complete, so do not bother yourself with times and dates too much. Since you are now cycling with fish, here is what you need to do....
1). You could return your fish to the LFS for possibly some in store credit and cut your losses. I know this doesnt seem like a good solution, but it is by far the most ethical and easiest. You can then allow your tank to fishless cycle...but I will not bore you with the details of that yet.
2) TEST, TEST, and RETEST! What you are looking for are high readings of ammonia, nitrites and nitrates. All are fatally toxic to your fish at high levels and if your tests reveal that they are high, you should do a water change to help lower these levels.
KEEP IN MIND...doing water changes to lower your levels of ammonia, nitrates, or nitrites is only going to help maintain your fishes lives for the time being. you could find yourself in the midst of a non stop cycling process in which you raise the levels of ammonia, nitrates, and nitrites and then quickly depleate them, not allowing the growth of benificial bacteria to occur. These bacteria are the same that will keep your water quality in check for the long duration. the process of cycling your tank is simply allowing enough of these bacteria to establish themselves, usually before you add fish.
So, if you have not done so, get yourself some good test kits. I do not suggest test 'strips' as they can be easily spoiled by humidity and not keeping them stored properly (under the tank, in the stand is not the best place, even if it is convient). Most LFS's will test your water for you using test strips, so if that is the route you want to go, just buy them yourself. I do recommend using the good old test tube type kits, all of which (that I have seen for sale) come with little booklets and color charts explaining how to perform and read the test.
If your fish do start to die off, this is most likely becasue your tank is not cycled and cannot process the chemicals mentioned above quickly enough. Do not buy more fish as this will just result in the endless cycle I talked about before.
Cycling with fish is often best done with mollies and platties (and some other super hardy fish) since they can usually outlive the high amounts of ammonia, nitrates, and nitrites. However, this is generally viewed as unethical because it does put strain and stress on the fishes in your tank. It can also lead to other problems later on in life if you happen to inadvertantly add a fish that has Ich. The stressed fish you used to cycle your tank will be easier to succumb to the disease.
If you do lose your fish or decide to return them to the LFS, simply feed your tank as you would if there was fish in there, and the good bacteria will have food to eat and time to establish themselves. I have tried some chemicals such as Bact-seed and Bact-feed with mixed results, but still I did not add fish until all my water parameters were at acceptable ranges and stable (meaning they stayed this way for a good period of time)
I wish you luck and please do not get discouraged. This is a common mistake. You may be able to get away with your tank as it is, but I would definately NOT get more fish until your tests say you can.
Two days ago I started off my new tank with four bronze cory cats, who are all happily swimming about in they're new home, and I was curious as to when was the best time to add more fish. I've read from 2-3 weeks. I'm thinking about adding a couple of platies, hearing good things about them, but I want to wait a bit so I don't mess up the cycling. When do you guys reccommend the best time is to add more fishies? 
I'll keep checking the nitrate and ammonia levels then (and keep your feeding tip in mind). Thanks for the tips!
Thank you so much for all of your help! It is so much appreciated, especially for a beginner like me! 
