What Causes Nausea Due To Food Smells With Tiredness?

I had my gallbladder removed 3 weeks ago, I've been on birthcontrol for 3 months but I was not able to take it while I was in the hospital. I have a lot of weird symptoms and I don't know if they are from the surgery or pregnancy. I've been having weird food aversions, certain smells make me nauseas, I am tired all of the time even if I take a nap, I have the linea nigra line which just started to appear in the past couple of days, I'm extremely emotional and I am going on 5 weeks with out period. I'm 25, active and besides having my gallbladder out I am extremely healthy.