I have had mirena in place for two months now...I have experience...

I have had mirena in place for two months now...I have experienced cramps, leg pain, constant bleeding, weight gain....so I went in today to get it taken out. The doctor refused to do it because they said those things had nothing to do with the IUD.....I have a heart problem and he said it is more dangerous to get pregnant then have mirena in me.....why is it his choice? I would rather get the pill after all I have experienced.....there is no reason for me to gain all this weight. Im pissed, I want it out but cant take it out myself. But why is it his choice?