I just need opinions! Please read all

I need someone's opinion. I have no one else I can ask so i come on here. My last actual period was in March. No signs of an actual AF. I started spotting Thursday. It lasted til Saturday. It was brown and a little pink the first day, red when I wiped once on Friday, then back to brown Friday after that before stopping on Saturday. This is all new to me. I have always had heavy bleeding. Since I was 12. I bleed so bad that if I wait over an hour to change my tampon, it's not pretty. It literally runs down my legs. So because I was spotting I thought I'd take a test and low and behold it was negative. Latest test was this morning and as you can see it's negative. I just want to know what else can cause spotting if I'm not pregnant?