I'm having similar symptoms of pregnancy but i'm on the pill?

Nothing 100%: rare but possible. More commonly it might be because of the pill side effect.

Do a pregnancy test: You can become pregnant while taking the pill it's not 100% effective. When taken correctly it's more than 99% effective. However, with normal use it's about 85-88% effective due to the fact than it's not taken correctly and users often missed pills. Do a pregnancy test to exclude pregnancy.