Contractions?

What does it feel like when you start having “real” contractions?

I’m 36 weeks and all last night and today I’ve been really sick (throwing up) and having diarrhea. I have cramps all in my stomach and back but nothing unbearable.

I’ve had morning sickness my whole entire pregnancy so I’m not super concerned with the puking part.

But everything I google says that’s a sign of labor so I’m freaking myself out! I already went to the hospital last weekend because I thought my water broke but I had just wet my pants lol so I don’t want to be the girl who cried wolf again.

How will I know if it’s really labor or not?