Back pain or back labor?

So I’m almost 22 weeks with baby #3, 4th pregnancy (my first I miscarried at 14 weeks). I am having really bad back/upper hip pain that feels a lot like back labor. Im not having contractions but I did notice a few times today that I period like cramping/aching in my vagina (like when you’re having cramps and you take a tampon out and your vagina aches, if that makes sense). It is constant but gets intense in waves. My belly isn’t hardening and baby is moving and kicking doing just fine. I think it’s just aches/soreness but the new cramping has me a little freaked out. Can anyone relate? Any tips on how to get it to feel better? The pain literally wakes me up at night.