If your back is hurting off and on and your belly gets tight when it hurts you might want to just let your dr know.
Could just be Braxton hicks, I get mine in my back sometimes and they hurt pretty bad.
Try eucalyptus shower gel/wash for the stuffy nose/ears. I started doing that every morning and I rarely have plugged ears/nose now
I'm 30 weeks this coming Tuesday and some days my ears feel like they need to pop/they're a bit blocked up, I can't hear people as well but I can really hear my own breathing. Seems to come and go!