BH/ Contractions/ Baby balling up?

So I’ve had the most smooth easy pregnancy I’d imagine. No symptoms of pregnancy at all, barley gained weight, just fabulous! Lately idk what I’m feeling.. period like cramps (but they don’t seem to be timetable as they last awhile, go away, come back) and with that I also feel my belly tighten then go loose again.. but it doesn’t match the timing of the cramping, I also feel baby moving a bit (I think.. like a balling up feeling but still hard) and nothing is painful or anything like that, so idk what I’m feeling. Also accompanied with this is a rather painful lower back. Idk what I’m feeling. Is baby just getting comfy? Are they Braxton Hicks? False labor (super high tolerance to pain)? Everyone says you know when you know, but I’ve spoken to my mom and she didn’t have contractions with me just “felt funny” went into l&d and she was already 10 cm, they broke her water (also she never lost her mucus plug) and within an hour of arriving at the hospital, I was born. I’m just curious. Asked my dr today he said all this is normal but couldn’t really answer what it was. 37w4d.