Help just got my first period?

ok on the 27th of june at night time when i was in the toilet i noticed a massive dark red of blood patch on my underwear i just ignored it because i was tired.The next day when i came back from school i saw some more blood so i just put a pad.The thing i want to know is when is it going to happen again and is it going to happen 2 days in a row so plzz help