pregnant period?

I've been having really bad cramps lately, a funny smell, and heavy spotting. I thought I was on my period again but I just got off of it two weeks ago. I've been checked for std's and sti's already so it's not that either. My coworker reminded me that I could be pregnant even though I've been on birth control. What could it be? Should I get a pregnancy test? I have an appointment next week with obgyn.