Engagement ring

We've been engaged since May 2016 and the wedding is October 2018. The ring he proposed to me with is very pretty and I will never forget that night. My problem is that it wasn't picked out for me - it's his mom's from an engagement that didn't work out (the guy cheated on her) and she kept the ring. I understand that he couldn't afford an engagement ring at the time (senior year of high school just before leaving for USMC bootcamp) but I can't help but wish that I had one of my own that he took the time to look for and when talking about wedding bands, a new engagement ring never comes up even though I've tried hinting of getting a new one. Another reason I want my own is that my mom and one of my friends mention about the ring having a curse of doomed marriage when they found out how he got it, so that's been stuck in my head... I need advice - what do I do?!