You're fine. A bit of blood is normal. Bruising is usually a sign of poor technique, but nothing to be concerned about, it just means you need more practice. Pip could be the gear, could be the technique. Keep a steady hand and push the oil slowly. If your hand shakes, the tip of the needle can slice up muscle fibers. If you push the oil in too fast, you can create a bubble that will push muscle fibers apart, causing them to tear. Try for about 30 seconds per ml to give the oil time to work it's way in. If you have to stop and start a few times, do that.
Google IM injections and find a diagram showing where to do it. Some spots have more nerves/veins than others, so just aiming for the thick part of the muscle isn't good enough. Even so, you will eventually hit something you don't want to, but it's not that big of a deal.