You were due for a depo refill the last week of January and couldn't get an appt until the first week of Febuary you had sex a day before your appt could you be pregnant?
There is a chance but it normally takes a while to get out of your system. If you are late for another shot, you shouldn't have unprotected sex until you get your shot again. My doctor always scheduled my appt for a few weeks before I was actually due incase I couldn't get in, I had extra time. Usually they will ask you if you have had sex since then, and they will make you do a pregnancy test before you can get the shot.