Low progesterone on suppositories

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On my first cycle of clomid plus trigger after mc in March and was started on progesterone suppositories 2dpo due to low progesterone with my pregnancy. Cd21 progesterone level was only 14 and they want it above 20 so adding progesterone shots daily. I'm so bummed but will do anything I need to for a baby!
Anyone with BFP on progesterone shots or having low levels? Any side effects or advice? (My butt muscle hurts already!)  
Beta test 8/3!