can I be pregnant while on the pill?

Natalie
So recently my partner and I decided to have sex without a condom. I am on the pill and have been on it for 5 months now. Last week I've finished my period on wednesday but I was taking the non active spill since I'm following the birth control packet. On Saturday I was on the active pill. We decided to have sex without the condom. He would always pull out before cumming but this time he cummed inside me...I don't know what this means. After that I didn't feel okay, not because of the sex but I was over thinking about the pill. During that night I would frequently wake up as would need to go to the bathroom to vomit...for Saturday night till monday night I needed to vomit....I'm scared to know if I would be pregnant....I'm not ready as I am currently still in university and wanting to get my diploma, and the same as my partner. 
Do you think maybe I'm just over thinking and it's causing me to become nauseated? Just need so advice. I've waiting for a week to go by so that I would buy the pregnancy stick to find out.