How long can you go without knowing that you have Aids?

Say you don't take a test.

When will the symptoms start coming up?
When will you start to see signs of the disease?
Whats the longest you can go without any problems and have aids that you are not aware of?

From what has been said, if you aren't tested for HIV and you indeed has the virus - you could go up to 10 years before it would turn into AIDS.
Now, you could have acute symptoms at the 2-4 week mark after the possible risk exposure. These symptoms seem like the common cold/flu like virus, though they seem to linger more so.
After that, who knows? It really depends on the person and their immune system. People could go for years without knowing they carry the virus, yet they will start to have a laundry list of problems occur probably a few years later (say 3-5 years). HIV begins to literally break down your immune system so again, it depends.

Well I think that nothing really shows up in a blood test until 3 or 6 months after contact with an infected individual and even so, at that time, it might only be in the HIV stage. Most of the symptoms mimmick those of the flu so a lot of the time, people take their symptoms as the flu and do not seek treatment. Signs can show up as early as a week or two after the virus has entered the system. Not everyone has such severe symptoms but like I said, most people brush it off for the flu and don't see a dr.
If you're concerned for yourself, I would suggest using a condom whenever you have sex to avoid transmitting the disease. But know that a condom does not always stop the virus as it can slip, break or have a hole in it. Know your partner and know about their sexual history and when and if they have ever been tested for STDs.

As long as you are in denial of what your body is telling you and knowing what your risk factors where...

Some people get a flu-like syndrome when they are initially infected, but this is easy to miss as being HIV (since it's so non-specific).

The time it takes to develop AIDS and subsequent opportunistic infections is 8-10 years on average, but this is HIGHLY variable. So if you miss the initial flu-like phase, it can be many years before you realize something is wrong if you're not tested.