How do you know you’re in labor?

Im a first time mom so I’m sorry if this question is foolish 🥺 it just there’s time I’m getting out of bed and I’m just like “oof my vagina hurt and there feel like a lot of pressure down there” and also when I use the restroom I feel like there’s so much pressure down there that I wouldn’t be surprised if I start to give birth out of no where! ( not literally but you get what I mean)

So now I’m questioning on how do I know when I’m actually in labor?

I know contractions is an obvious sign but I also question on how do you know if you’re experiencing contractions?! I’m confused on what contractions are and how to tell 🥺

I’m currently 34 weeks and baby is head down now so that’s why I’m questioning even more as my doctor informed that it isn’t a shock when mom give birth earlier than expected especially with how many weeks I am