Could I be pregnant?

Ok me and my boyfriend had unprotected sex while I'm on the shot. And now I have really bad nausea and sore breasts. But because I'm on the shot I don't get my period so I don't know if I would be or not because I won't know if I missed it. And the other reason I ask is because I'm on the shot. 
Last night I had a miscarriage. But I'm still having really bad nausea and stomach pains. Could it just be from the miscarriage..