Cramps / Contractions?

So I’m 38 weeks tomorrow. All day I’ve been on and off having period like cramps. They’re mainly in my lower back but some move to my lower abdomen. I can’t really say it feels very “tightening” but I’m not sure. This is my first so idk what contractions really feel like. Are these considered contractions or are these just basic cramps of pregnancy? I’ve had cramping for the last few weeks but it happens then goes away for hours. These are more of it happens and I get uncomfortable then it goes away for a few minutes then comes back. Any advice would help. I’m a ftm and I have no idea what to expect or look out for.