Underactive thyroid and conceiving.

Hi ladies I'm 22 and me and my boyfriend have been together for a over a year and have been trying for 3 months.

When i was 19 I had skin cancer and had an op to remove it all (all good now) after that obviously I get monitored regularly and lately iv had blood tests as to whether I have a underactive thyroid. I'm just wondering if it came back positive does this affect getting pregnant and how? Thank you in advance for any advice!