So, I usually start my period on the 24th-26th day of the Month, its been 3 days and no period.. I have yet to take a pregnancy test but I think it might be too early?

Earlier this month around the 5th (a couple days after my period) I had some light bleeding for three days, I'm not sure if it's a symptom or if my body was getting rid of the rest of the blood from my period.. not sure.

I haven't really experienced any symptoms I don't have morning sickness, I don't have sore breasts and my appetite is pretty much the same. I did experience some difficulty using the restroom a day ago. And I read that constipation can be a symptom.

I am really scared , could it be my body changing cycles? Or something a little more serious? The bleeding from the 5th is really the main reason I'm freaking out. Please help.

You should be worried about pregnancy if you aren't using a safe birth control!
3 days is way too soon to test.
3 days is not 'late.' Even women with very regular cycles are going to have months that are off a bit. Saying you start on the 24th-26th isn't meaningful anyway - months don't all have the same number of days. Count days between start instead.
Yes, you could be pregnant. Symptoms or lack thereof are not indicators; only tests are.
Worry can delay or stop menstruation.
Spotting is nothing to be concerned about either. It can happen any time. Some women spot during ovulation, which is usually but not always mid cycle. Or it could be the rest of your last period as you suggest.
You sound like you haven't been menstruating too many years? You will probably go through various changes month to month, year to year, as the rest of us have.

I've been reading a lot lately about people saying its to early to take a pregnancy test! If u have missed a period then take a test even if its one day after a missed period, and it doesn't have to be your first morning wee(yes it will be the highest hcg level but if your pregnant then your pregnant so I don't really matter what time in the day) I was four days late when I done a pregnancy test and I did it at 8:30pm and the result came up within seconds! So if u want to do a test then do one do what u need to do so u can put your mind at ease, good luck :)