Could Frequent Urination With Burning And Lower Back Pain Be Due To Labour?

I am 38 weeks pregnant and woke up with severe urinary pain - frequent urination, burning and lower back pain (also some abdominal pain). Top of my stomach has been tightening all day - no timed consistency. Went to an urgent care and urinated in cup - they said it wasn t a strong reading of bacteria but gave me antibiotics, and Azo ... Have taken 2 Azo twice and no relief. Could I be in labor and not have uti