Injecting follistim in the muscle

Jennifer • 42, TTC #1 +3 years, AMH 0.15 & 0.325, DOR. 4 failed IUI'S, male factor, no response to ivf meds. 9/4 DEIVF=bfp = MC 9/28, DEIVF 1/4/19 BFP born 9/25/19

my RE told me to inject the follistim in the muscle and gave me syringes to remove it from the little Tiny needles and give it to myself in the buttocks. not sure how I'm going to accomplish that but anyway. did anyone else have to do that?