No, aspirating is done to make sure you arent in a vein while you are injecting, most likely you went through a vein pushing the pin in, but werent in one when you injecting... As long as you used a correct length pin and stuck it all the way in, the gear should no have been leaking out with the blood... IF you had injected into a vein you would get a combination of a bunch of different things from light headed to cold sweat to nausea, etc... So I think you're fine....
YUM