preg on pill?

here's the story: i have been nauseous since last wednesday. i take my pills around the same time every morning. i do sometimes have diarrhea in the morning. i started a new medication (i hadn't had sec since july 5th. he pulled out. today, a huge wave of nausea took over me today. i also felt like i wanted to pass out. i ran to the store bc i got scared so i got 4 tests and 1 was negative. my period is on a week

shouldi be worried!