Are Spotting,nausea And Mood Swings Signs Of Pregnancy?

Hello! I have been married for nine months. My husband and I were waiting to have children, but I recently have been experience some unusal signs. Last November I ran out of my normal birth control pills. I went one month and half without taking any pills. I have a older sister who is pregnent and she sent me three packs of birth controls that she had. I started taking those right after my last period. I took them for two week and the week before my period was going to come I started spotting and cramping. The spotting and cramping lasted for one week, but my period never came. Lately, I have been having headaches, moody swings, nausea, and fatigue. I took a pregnency test a week ago and it was negative, and I have a Doctors appointment this week. I was wondering if I am over reacting or not?