i am 19 years old.I started my period when i was in 6th grade. My periods have been normal (for me) and regular lasting about 7-8 days. But about 2 months ago my period started lasting 11-12 days. And it wasnt as heavy as normal. My period after that lasted 12 days aswell. A little more heavy bu not much. Then my last period i just had lasted 19 days. It was a nomal period for me at first. After the 10th day i started spotting. When i would use the restroom sometimes there would b just a little blood. sometimes nothing at all, sometimes a bright red but just a little, then other times it was a thick brown/black color. I have been a lot more tired latley, hungry, moody, emoational, bloated, sore nipples. People tell me im pregnant but every test i take is negative. What do you think?