What does early labor feel like??

Hi ladies! I'm 39 weeks and a few days, FTM and as of last appointment I was 2cm, have been losing my mucus plug the past few days. My Father in law took us out for dinner tonight to Chilis, thought I would get a  nice spicy enchilada. Now I am feeling some tightness and discomfort in my Lower stomach, it comes and goes but not like a pattern. I'm just confused if it's gas pains from shitty chain "Mexican" food or could I be feeling early labor? I'm confused!