Progesterone - pill or cream

Maria
Im in my TWW after 1st <a href="https://glowing.com/glow-fertility-program">IUI</a>. My lutheal phase is often way to short (sometimes 8 days), so I asked for progesterone after the <a href="https://glowing.com/glow-fertility-program">IUI</a> was performed. My dr gave me cream to insert for 14 days and Im hoping this could sort it out. I know some are given pills instead though - do u know why that is? What are the differences in the effect of the different treatment strategies? My dr doesnt seem to care that much about my short L phase and I had to ask for the progesterone treatment myself så Im unsure if this treatment is really the best suited. Thankful for feedback and also, thankful for something to fokus on during the TWW...