Prometrium?

Hello! I got my blood work results a couple of days ago and my doctor prescribed me progesterone suppository "Prometrium 200mg" vaginal capsules.. I started using them today. I inserted one pill through my vagina this morning and by noon I saw thick orangish mucus and for a second or two I was terrified that I was having a miscarriage.. But then I remembered that the capsule is orange in color and the doctor said I might get very faint mucus bcoz of it.. But I'm scared to use it again.. I mean it filled my panty liner.. Is it normal????