Progesterone shot questions

Destiny
Does anyone know how safe it is to have more than one injection done in one week? My insurance is playing games and this Saturday I'll already be 2 wks late on the shots and am
Worried that since I've missed one already and it's looking like a second it won't be as effective :( just a nervous already micro preemie mommy who wants to do everything in my power to prevent it again!