Crystals in urine??

I went to my ob yesterday because I've had side/ back pain and have noticed my urine has been dark. He tests my urine & he says I have crystals forming that if I feel worse to let him know. Last night I started passing mucus looking discharge with alittle blood but it seems to be coming from my bladder not vaginal! I'm 32 weeks & I called my doctor but they aren't in until 2. Any advice would be appreciated! Thank you in advance