I Had My First Mammogram 2 Weeks Ago. They Saw

I had my first mammogram 2 weeks ago. They saw something on the xray and had me come back for additional xrays and an ultrasound last Friday. Today they called and said the dr doesn't think its a cyst and they are scheduling me for an mri...what are they looking for on the mri? if its not a cyst, does this mean they believe its cancer?