I've take 3 pregnancy test the past couple of days and they all have came back negative. I've never been this late on my period before. I've had headaches a lot.. im always tired.. ive thrown up once and that was yesterday.. ive had cramping but it isn't for long and the best way I can describe it is like a period cramp but not as severe and it only last a little and it would come one day and then a few days later ill cramp for like 5 min. and then its gone

It's possible, sometimes a pregnancy doesn't show up for several week on a urine test. Could also be you are ill and that has caused your period to be off.

Given the late period, and other symptoms you have experienced, it would be a good idea to see your doctor and ask about having a blood test done. They will likely do another urine test at the office as well.