Brown discharge or first period

I really need help so at school I noticed some brown discharge on the front of my underwear and it’s all dry and like a light brown, im not sure if it’s my first period or if it’s just discharge and I need to know if I should start wearing pads.

I noticed this maybe like 2 hours ago and I don’t think there has been anymore since and there’s nothing when I wipe. I have had all the signs for a couple months now but I really need help