Help ‼️

Hello , I had my period after one day missing . I had a terrible pain in pelvic zone . I said it’s one of that awful period . It was so much blood , I usually change like 5 pads per day now I changed 3in 6hours .... In next day I still had pain but not that intense and the bleeding was really light ... And the third day I didn’t had any bleeding ... I don’t know .. It’s frustrating cause is my first period with 2days bleeding ... What could be that?