CVS Specialty Pharmacy through CVS Caremark

Hi all, I would like to hear about your experience with CVS Caremark for IVF. I have CVS Caremark insurance and it seems like CVS specialty pharmacy is a preferred pharmacy. I wonder if this option would be the best for me, or if anyone experienced to found another non-preferred pharmacy was actually cheaper than this preferred pharmacy for certain medications. I am also curious if there was any delay in medication delivery with CVS Specialty Pharmacy? Please share any experience or any feedback on CVS pharmacy. Thank you.