Hello,
If you had intercourse in the first week after starting the pills then chances of pregnancy are there because pills take atleast 7 days to start their action. The pregnancy symptoms include absent or delayed period for more than 10 days along with morning sickness, vomiting, frequent urination, feeling tired, tenderness of breasts, light-headedness, feeling dizzy, getting irritated, and increase sensitivity to smell.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
You can read the package insert to tell if you were protected at the time you had sex, assuming you've been taking the pills properly (same time every day, no misses, started Sunday after your period started).
The pill works by keeping your body from actually ovulating. No egg = no pregnancy. You shouldn't actually feel pregnant while on the pill.