Should I be completely honest ?

Hi everyone, I’ve recently been diagnosed with breast cancer , following this I’ve had a CT scan and although they said it hasn’t spread anywhere else ( thank god , I was so anxious about the results,I nearly passed out ) but they did say the saw something in one of my lungs . They said that they don’t think it’s anything to worry about but will give me another CT scan in 3 months to check on it . At first I thought , I won’t tell my family etc as I didn’t want to worry or upset them further. Have I done the right thing holding back that information?