How long after you lost your mucus plug did you go into labor?!

FTM here. I will be 39 weeks on Wednesday. I lost my mucus plug yesterday morning first thing and was fine u til late afternoon when I started having some painful contractions but they haven’t been very consistent. Any idea of how long after you lose your mucus plug that real labor will start?! I’m freaking out that I won’t know what is real or not. 😕