FTM and baby moving around

I’ve felt some pressure in my lower abdomen (I’m around 18 weeks) and my stomach sometimes feels like it does when you’re on a roller coaster like it’s flipping. And I decided to chalk it up to maybe the baby was moving or flip flopping around. And I was talking to some other people about it and they said that was stupid to think that, that I’m not far along enough to feel any movement. Inside or out. Anyone else have any opinions? I feel stupid and ashamed now.