Contractions Question

Lacee
Hello mommas! FTM here so I kind of need some advice. I'm 39 weeks today. Can contractions just feel like period cramps? My entire pregnancy I've never really had contractions that feels like your stomach tightening up or anything like that. They've always just been like bad period cramps with back pain. But the period cramps don't come on and then go away and start up again, they basically just stay there. Bc of this I've never really had contractions that I can "time". How can you time these? Or can you? I know I'm having contractions bc I'm 2cm dilated and 75% and I have been losing pieces of my mucus plug for 2 weeks now. But I'm worried that I won't know exactly when to go to the hospital bc I can't really time them so I don't know how close or far apart they are. I have a drs appt tomorrow so I'm going to ask her but I'm hoping I can get some advice and answers. Thanks!