Am I pregnant or paranoid?

I have not had unprotected sex, my boyfriend uses a condom and checks it each time and I use birth control (YAZ) although admittedly not at the same time each day, within a few hours or so at the most. The condom has never broken or had holes. I am concerned because it is a week before my period and I have brownish discharge and a weird fullness and pain in my stomach. I already went to the doctor and I came out mostly negative for a UTI. Do you think it is probable or just that one case out of a million sort of thing that means I am probably fine? Thank you and know that I am of age and in a committed relationship.