I have had an IUD for the past 6 years. I did not have the IUD checked for the past 3 years also had no intercourse for the same amount of time. I am sexually active again what are the possibilities of getting pregnant?

There are risks beyond just a pregnancy... such as any number of STD's... HPV (most people with it don't know they have it), AIDS, and the others...

As far as the IUD... you should payu a visit to your Gynecologist for peace of mind.