I am a 32 year old female. Have low back pain that goes from about tailbone/above butt crack and into my left hip. Is fine in am, gets worse as day go?

See PCP. It may be a herniated lower spine disk with sciatica. See your pcp and maybe have an MRI done. At night you are prone, less pressure on your spine, but during the day you are active , lots of pressure->pain.
? Sacroiliitis. You may have si joint dysfunction or sacroiiitis. People often develop pain over there jean pocket, try to sit with that butt cheek off the chair and hurts to turn there leg out. This may respond to rest, anti-inflammatory, physical therapy, belt, steroid injections or surgery. I would discuss it with your doctor. Good luck!