My mother always used to tell me "I wish you were more like your brother", strangely she would tell my brother the same thing. It turns out that that she had a miscarriage.
Is this really something your mother says?
Oh, she is against pregnancy and babies
It's not very nice to joke about a miscarriage. You should read up on miscarriages and understand why it can be such a horrific event for women.
I can say what the fuck I want.
Miscarriages are a serious emotional setback and no joke will make people laugh at the issue. Just because you have the right to say what you want doesn't mean you should say things that are hurtful to others. Why not find some topics to joke about that everyone will find funny?