It's hard for me to say because I have a previous back injury from work with the exact same symptoms, but it's definitely flared up and gotten 10 times worse with pregnancy. I'm 27.5 weeks and it's usually worse at night. It's so bad that I yelp and last night getting up to the washroom I had to grab onto furniture to hold myself up because this sharp pain came on so bad and so suddenly. I honestly don't know what to do. My ob is aware and ordered physio for me, but I have no idea until then. Heat no longer helps. It's just one side of my low low back and I don't know if it's sciatica because it usually doesn't travel down anywhere. Just a tiny bit into my bum.