Why the pressure to get married?

I am 27-years-old and have been dating for almost three years now. I always felt I would get married when I was sure I had time to stay home and look after my child. No offense but I don’t want to be one of those mums who barely have time for their own children because they have work and go back home tired. My boyfriend (he is 33) and I have spoken about marriage and neither one of us is in a rush. We love each other deeply and there is no doubt that we will get married eventually. But my family has become a problem. I live with my mum and dad and younger siblings. I am reminded constantly how my biological clock is ticking and that I am not getting any younger. The other day, my mum said people were starting to think I’m bewitched since my boyfriend hasn’t proposed yet. She added that even my younger sisters would get married before me, which will confirm the witchcraft sent my way. My father says that the only thing that will come out of my relationship is a baby out of wedlock and he will not be a part of that. I have told them so many times that we will tie the knot when we are absolutely ready to but all I get is what’s the hold up? I now told them that I plan to move out and cohabit with my boyfriend and they acted like I told them I was part of a terrorist group. I want to move out because I can’t stand their constant nagging – I need space. I’m not being insubordinate or anything, I just want to do things my way because if I rush into marriage, I will resent them later for pushing me when things fail – though that seems like a risk they are willing to take. If I stay home I will lose my mind and if I go, well there’s no telling just how angry they’ll be with me. Please help. Cindy