Possible preterm labor?

Mina
I woke up with back pain a few times last night starting at like 3am. Got up at 6, 7, and 9am to pee. Since then when I properly got up for the day I've been peeing like once an hour. My back pain has been normally higher than where it is at the moment, it's really low at the moment. I'm getting a lot of pelvic pressure. I'm also having light cramping along my panty line and lower belly every so often. My baby isn't moving a lot, I'm getting small movements, but a week ago he would be kicking me so hard it hurt me. He already is head down and dropped. I'm 31 weeks now, but I lost my mucus plug at 24, 26, and 29 weeks in larger chunks and between those weeks to now in smaller chunks. I lost more today. I'm worried I may be in preterm labor, but I haven't had any contractions that I can tell are contractions. I haven't had any BH contractions either though. I just don't want to be that lady who thinks there is an issue and there isn't one. I'm a ftm and I just want to make sure that the baby is okay. At my last ultrasound, 30 weeks 3D ultrasound, he was looking really tall for how old he is. I called my midwifery and left a message at their nurses station because I don't want to call their emergency line unless it actually is an emergency.