What’s going on?!

So this is my second pregnancy but this is so different than my first. I am 32 weeks pregnant and been losing my mucus plug which can be normal I know it can grow back but last night I woke up with extreme lower back pain that came in waves and would go into my lower stomach too. Are those back labor contractions? I have no idea what’s going on if I should get ready for her to come early or if this is just going to happen until I’m full term.