I used clexane injections on one of my cycles, they are not the nicest things but I did find they got easier once you get the hang of it. I am assuming you are using the pre filled syringes? I found them really stiff so I learnt to loosen the plunger (I think that is what it's called) first to move the liquid to the top of the syringe and to let out any air. It meant that once I put the needle in I wasn't pressing so hard to inject because it was so stiff. Plus make sure the sharpest part of the needle is closest to your stomach, so the hole to the needle is facing upwards. I also alternate from left to right on my tummy area below the belly button. Unfortunately I did get bruises, some worst than others but I promise it does get easier. I hope that makes sense and is of any help.
Congratulations on your transfer and wishing you the best of the luck.