It be better if you go to the doctor and find out because that happen to me I did not come on my period and I had taking 5 pregnancy test and they all said negative.so 2 days later I want to the doctor office and found out I was pregnant.
I always felt the same exact pregnancy symptoms you mentioned, two weeks after conceiving. In my 3 pregnancies, I was miserable with nausea, migraines, heartburn, fatigue, etc.
But now, I'm 7.5 weeks with my fourth child, and do not have severe pregnancy symptoms, at all. I went to the Dr thinking I had high blood pressure or something but instead, I was 6.5 weeks pregnant!! I only have occassional food aversions and fatigue.
All pregnancies are truly different. Never in my wildest dreams would I have EVER thought that I wouldn't have severe pregnancy symptoms but I don't.
I now truly believe that everyone reacts differently to pregnancy AND to different pregnancies.
A pregnancy test should detect pregnancy if you are over 2 weeks late. Go to the doctor for a more accurate blood test, then you will know for certain one way or the other. It could just be your body readjusting to not being on the pill anymore.