quick question

Ok, so a little over a month ago I had sex with I guess I could call him my friend with benefits for the first time. I took plan b the next morning and I got depo provera exactly 2 weeks later. Of course I was given a pregnancy test before I got the shot and it came back negative. At the same time I got the shot I was also spotting. My periods have been irregular these past few months, so I had my last period a couple of weeks before I slept with him. According to eve I was supposed to start my period 3 days ago, but it hasn't. I haven't really been feeling that well this week. I'm sure I'm not pregnant but i have this little feeling nagging at me. Something in the back of my mind is telling me to take another pregnancy test. I know I'm probably over thinking it. I guess what I'm asking is should I take another test or wait a week or two to see if my period starts?