Do you have lower back pain?

I'm 11w4d and the past 2 days I've had very bad lower back pain right at the base of my spine. I'm worried I'm so early in pregnancy I don't get why it would hurt this much when I haven't gained much weight. I cringe sitting down an getting up. I could have tweaked something.

Any of you having real bad lower back pain? It's kind of like pms pain but more sharp?