Age concerns?

I'm 21 y/o next month and ttc, I was told a few months ago I have multiple fibroidadenoma's and it was recommended I have my children young to reduce the risk of them becoming cancerous. I am 5 days late and don't know if I'm pregnant yet as I haven't taken a test. I'm scared of how my family will react if I am, does anyone have any recommendations on how to tackle family members who may be unsupportive?