I Developed Hives Yesterday, After Five Days Of Being On

I developed hives yesterday, after five days of being on progesterone to help induce my period. The hives have only affected the lower half of my body, and back of my arms. The hives have now turned brown. Is this normal?

Background: I have several autoimmune issues, and am allergic to many drugs. This reaction is not a total surprise, but the hives staying on this long an turning brown is something new.