2nd trimester pains

Danielle • Pregnant with our first baby! Due Jan 3, 2016. We are over the moon!
So, I'm 15 weeks pregnant and for the past few days I have been having some pretty intense lower back pain. Mostly towards my kidneys and sides and I am getting a little concerned. I know back pain is totally normal in pregnancy, but I thought it usually affected women in the later months. Is anyone else experiencing this or has anyone experienced it? The pain doesn't bring me to my knees, but it does make me yell out, especially when bending or squating.