Hello, I would be happy to help you with your question.
Cancer of the uterus
is incredibly unlikely. It sounds like you have a large fibroid
of the uterus that must be close to the lining (where a pregnancy
might implant) thus producing the "thickening" that they see. Given your age and these findings, the most efficient course would be:
1. Schedule an ultrasound
called a "sonohysterogram" - this will better define the fibroid and surrounding uterine lining.
2. If the fibroid is impinging on the lining significantly, consider having it removed
Yes, it can affect your chances of getting pregnant.
I hope that this helps and good luck!