Your preterm labor symptoms..?

I am 33 weeks pregnant and have started experiencing really uncomfortable lower back cramping every so often (around the night time)... and I have started not to feel good this week (nausea). It never lasts super long but it is so uncomfortable. I am having Braxton Hicks but none that are consistent. I'm also feeling super weak lately. I was just wondering if any of you moms have gone into preterm labor before and experienced these things? Or am I just overthinking it? (I really have a gut feeling she'll come early but not this early.)