Ladies please help. What is going on with my body?

Not on any form of hormonal birth control. 23 years old. Have always had a normal 28 day cycle that lasts 4-5 days -like clock work. Never have PMS symptoms(no cramps,tender , or ariolas or spotting). the past 2 months I have had all of that - Spotting a week before my period, pink discharge, cramps,tender s, and ariolas,strange twinges in either side of my pelvic cavity. I have not missed a period last month it was 2-3 days late and came but is was light and lasted longer than usual 7-8 days. this month it stopped after 2 days? and my are still slightly tender and my sensitive. Have taken a number of pregnancy tests and all negative. What are the symptoms to the cancers/illnesses that affect us ladies ccuase I am getting worried.