Period hasn't come.negative pregnancy test.nausea,vomiting,flank pain,decreased appetite,feverish,dizziness.dry eyes,trouble walking,abdo pain.help?

Urgent care or ER: It can be many things. Extrauterine pregnancy is part of the differential. However, you can't rule out appendix issues, amongst others. This is more concerning because you have fevers. Question is what is causing the inflammation? At the very least, contact your primary care as they will have an opportunity to do a complete exam and compare with your past history.