When will I get maternal instinct?

I've been waiting for a while, but it is not coming, my clock is ticking, I'm 33. I didn't have a healthy relationship with my mom and she left me for 7 yrs when I was 12, she was abusive and bipolar, told me many nasty things how she regrets being my mother, there was lots of abuse that made me stronger than most people I know. I still love her in my own way as I believe there is good in her as well. I think sad past is blocking me from developing any maternal instincts. What if I deliver and regret it the second it happens, or fail miserably, or feel I lost my life to some pooping and screaming creature that will send me to assisted living when I'm old? My family says it is the biggest mistake to have kids because there are too many people anyway. I won't get any help from my or my hubby's family. My mom already said not to count on her for help and that I should have an abortion if I get pregnant. However, when I see kids I get that fuzzy feeling of innocence and joy.