I just think that tomorrow is gonna be saturday and I wake up at like 4 am.

No jokes.

Don't pee before sleeping. You will wake up MUCH earlier because your body really needs a leak and it wakes you up.

Lol, i always do the other thing

That is a very, very bad thing to do.
Heavy sleepers wet their beds.

regards, person who has experience about the case

So it is a joke ._.

my Brother wake me up
and i dunno how my brother wake up on time

Probably some ringtone on his phone

a complex series of pulleys attached to a bovine that swallowed my cell phone

in reality, my parents tell me to awaken because i sleep through everything else somehow

For heavy sleepers it's bad.
People who don't wake up even if there was a thunderstorm outside, like me.

For more shallow sleepers it's okay, but there's still a bigger chance to wake up in the middle of the night instead of early.
and there's still the chance that you're too tired to go to the toilet and instead wet your bed.

Too risky. Then again, I have only "tried" it once.

Correct. Forgot about that.

New suggestion:

Use alarm and put it somewhere near your pillow.

If that doesn't work, use that old styled and traditional, "trrrrrrrrrrnnnnnnn!" alarm.

Will wake up your body and soul too.