No period, 4 urinal test negative

So, I feel ill, nausea, back pain, appetite and colon problems. Since I had the IDU ( almost one year) my period was regular with the symptom mention before. My period is not here 15 day delays. I did 4 urinal test negative. I’m afraid to be pregnant.

Before I use 5 year implant for year and half and for one year I did not have my period.

Should I be worried about it?