Okay to start, I am 20 years old, and I was suppose to receive my period on Monday the 24th but have yet to get it, I had nausea/vomiting the last week or so throughout the day, cramping like feelings, like a period is coming, lower back pain, sore breast, now its gone, I took a pregnancy test and it came back negative. Should I believe the test and just go with not Pregnant or what should I do?

It's possible, depending on how long you've "been pregnant" supposing that you are, for the test to have been inaccurate. But you could have also been I'll or there is something else medically going on that needs to be checked out. But it's only been 2 days.
You could get your period soon, but from the way it sounds, you very well could be. I recommend taking another test here in about a week or going to a doctor. Good luck!