I Started Getting Severe Wrist Pain 20 Weeks Pregnant, The

I started getting severe wrist pain 20 weeks pregnant, the wrist pain did not go away post partum, my thumbs will lock out of place some days. I'm now 11 months post partum and the pain has got better because I now only have it the week prior to mensruation, and during, so 14-16 days out of 28. The pain is still very serve during this time, Tylenol and Advil don't help at all. What causes this? Is there anything I can do?