Worried

I am little bit worried now, I missed my period last month and until now I still did not have one. I don't know what is going on since I have IUD for two years. Is it possible to get pregnant with IUD? I am freaking out! I am not ready to have another one yet. It's too early but if it is God's will then I will embrace it heartly. I am going to buy pregnancy test this weekend, I need to know if I am pregnant or not because if I am, then it's risky for the baby to have my IUD and I need to see the doctor right away.