Pregnancy second time around

Hello everyone! It’s been a while since I’ve been on here. My fiancé and I think I could be pregnant based on when my app says I ovulated and what not. The thing is when I was pregnant with my first baby I knew like 3-4 days after conception. I am still a week away from my period but I don’t feel any different yet. Any advice or information about other and what differences their first full term pregnancy was compared to their second? I am getting excited but again I don’t have symptoms at all so it’s also making me feel like I didn’t fall pregnant.