You see I went to the bathroom yesterday, and I saw some blood in my underwear. I know it's not my menstrual cycle because no more blood came out when I went to the bathroom other times of the day.

I saw your other question... you asked about a menstral cycle coming early. You might want to go see a doctor. I am confused. Are you having a period early or are you just spotting?

My menstrual cycle must have came

What is spotting?
i saw your other question...you asked about a menstral cycle coming early. you might want to go see a doctor. i am confused. are you having a period early or are you just spotting??

Spotting is just small amount of bleeding... sometimes happens at the start of a period or the end, sometimes midcycle or at the time of ovulation for some women.