Please help

About 2 months ago I had a month long period... I visited a dr and I felt like I wasn’t being taken serious... they said it was normal and to just go home... now again I am having a weird period it stared as spotting about 5 days ago and remained spotting for about 2-3 day now it’s getting heavier... the blood is between a very VERY dark red and a very bright red. Usually my periods last 3-4 days. Has this happened to anyone? I’m only 18 but I have been trying to convince for about 9 months now and nothing I’m really scared that there is something wrong with me 😔 if anybody could help I’d really appreciate it❤️