Arguments over pregnancy

I’ve become pregnant at aged 21, and honestly it wasn’t intended. I’ve recently been unwell for roughly two months now where every time I drink/eat I’m sick. I can only assume that in the mornings when I’m throwing up, I’m also throwing up my contraceptive pill. My fiancé started wearing condoms as a precaution, but it must of been too late by then. I KNOW that when I tell my parents there will be arguments. We own our own home, are engaged and have good stable jobs. Realistically by mother has nothing to guilt me with, but I know she’ll try and talk me into abortion. I REALLY don’t want this, and am prepared to fight, I just honestly don’t want to be arguing with her, I don’t think it will do myself or the baby any good. Does anybody here have any similar stories that turned out well in the end? Or any advise? I need a little bit of hope as I’m feeling a little bit scared.