I have an IUD and during sex I get this pain on my right side of my abdomen/stomach area!! What is it?

I had my IUD put in Feb 2011 and have had then in the past. The one in the past was removed due to pain during intercourse. My Doctor wanted to me to give another chance due to the medicaitons i'm on I need to be on something strong for birth control. But everytime now during sex with my husband I keep getting the sharp hurtful pain on my right side of my stomach/abdomen area; everytime he penitrates deep. it hurts so bad we cant have sex i'm in so much pain it's not pleasureable any more...