progesterone in oil injection

Fei
Hi, I'm starting my first <a href="https://glowing.com/glow-fertility-program">ivf</a> cycle and trying to decide if I want to do any fresh transfer.  For those who has done fresh transfer, were you required to use progesterone in oil injection?  Is it a lot more painful than taking shots at the belly?  I was told I will need to do the injections for 5-6 weeks (assuming the pregnancy is progressing).  If I do frozen transfer, then I can use progesterone suppository, which sounds a lot less painful.. how was your experience with progesterone in oil injections? Any advice is appreciated.