Some general advice - finish your school work and get a good backup as your computer can wait for a week to get service. If you can, call Apple and get the incident on the record now - just in case your warranty expires in the next day or two it's a lot easier to get someone to bend the end date if you did your part in letting them know you want help and have a reasonable situation to not bring it in.
That being said - if you really need this and your Warranty is ending and you don't want to depend on the kindness of someone extending that deadline - get it in for service if that is the most important thing.
As to the problem itself - it's pretty clear that you have a large white spot the size of about 16 complete pixel elements. Since LCD panels have back lit white light and several layers to prevent that light from escaping, it looks like those layers have broken down or not been formed in the first place. Both manufacturing imperfections and failure can cause sub pixel bright spots and even rows of failures if the control wires fail - but for a round spot like this to fail, the cause is almost always a physical damage that cracks the several layers of polarizer and lets light through the LCD assembly despite the transistor signals calling for the pixels to be dark like the surrounding area.
I would expect warranty to cover that sort of thing on either very new equipment or when there is absolutely no sign of external force and the company was being very lenient in not presuming that this was physical damage. I just can't see most people not noticing that size of a defect in a LCD panel at the time of manufacture or when you first started up the mac and had a dark background showing.
I would arrange for service at your earliest convenience - and if it gets repaired under warranty, great. If not, you'll know what a paid repair will cost and you can decide what to do with your time and money. I would ask them to quite you the in-warranty and out of warranty costs if you need to send the Mac in and can't let a trained technician look at it first hand.
In the mean time, you can see more about how sub-pixels are arranged on iOS devices and perhaps that will help you relate to the picture you took of the larger pixel areas on your screen.
And certainly don't try to fix it unless you want to put in a new LCD as a DIY or repair by someone that does that sort of thing. There's a lot of nonsense about massaging pixels and this would get worse if you push on the display - not better.