Progesterone supplement for estrogen dominance

I was just diagnosed as estrogen dominant among other things and I have a question about progesterone. He wants me to take progesterone 75 mg (natural form) from day 14-28 of my cycle..... He asked if I wanted pills or cream. I said pills and now I'm wondering what's better?? Anyone have any insight?

Also, I have Interstitial Cystitis and was curious how this would effect it....will it make it better or worse?

One more thing....I have a high platelet count due to not having a spleen and doing some research, I just read that taking natural progesterone can cause blood clots. This makes me kind of nervous. Does anyone know about this?

Thanks!