I take contraceptive pills, and have a regular sex life. Yet nowadays I feel sick

I also feel unwell and nauseated in the morning (sometimes even in the afternoon). I have taken the pills regularly except for one case when I took them a little later than usual, but according to the patient information leaflet, a few hours of delay should still produce the effect. My last period was not like it used to be, but as far as I know this could be because of the pills. In recent weeks, I have also experienced white secretion. Could these symptoms indicate pregnancy? 

It is very unlikely that you got pregnant despite taking the pills regularly. If your last period was different from the usual, you should nevertheless take a pregnancy test just to be sure. If it is negative, you can calm down completely. If you continue to feel sick and nauseated, you should visit your GP to undergo further examinations, if necessary.