a bubble or two is nothing to worry about. don't shake the syringe. hold it upside down so that the pin is pointed towards the ceiling, flick with your finger 2-3 times bringing the bubbles to the top of the syringe and on top of the liquid. inject into the air pointing AWAY from you and anyone else. the air/bubbles will come out with a tiny drop of liquid.
if there is a bubble or two in the syringe u cant get out, dont worry bout it.