Sisters

So I'm the youngest out of 3. One of my sisters just found out she might be going into early menopause and has no children and the other is currently booked in for scans to see if she can have children. Before we found this out I always said my sisters would be the first people I would tell but now I honestly feel lost because it would feel too heartless to tell them that I'm pregnant after what they are going through right now. I feel really lost because I'm so close to them and to keep this a secret is the hardest thing I've ever done. I don't know if I should tell them or not.