New Mattress Problems?

I recently started having back aches in my lower right side to the point where I feel nauseous.. it only happens occasionally but it seriously hurts to sit, stand, or lie down.. I think it might have to do with the way I sleep or the fact we just got a new mattress in September, but we do have 2 inch memory pad on top of it.. any suggestions on different sleeping positions or things that can help it go away? (My husband pops my back when it's hurt in the past & it's helped it feel better, but do you think he could've popped something out of place?)