dumb worries wifh depo shot


I've been on the depo shot for over a month. I didn't get my period last month but I did start bleeding a little this month. my bf is visiting from South America. we had sex and didn't use a condom, but he pulled out. I'm still freaking out wondering if there is any chance I could be pregnant at all. it was Thursday night. I was even looking at Plan B. even tho there was no FAILURE or lack of birth control. I'm just paranoid and need reassurance!