Is trace amount of e coli in urine with lower abdominal pain okay to ignore or treated at home with cranberry juice/azo? or is it likely to develop into female uti?

Nothing can be ignored in medicine, it does not sound that so far your culture met criteria for antibiotic treatment, it is hard to predict otherwise, good hydration and staying in touch with your doc would be best.

You are doing the right things. 'Trace' of E Coli is not a proper report of urine C&S and in a urinalysis E. Coli can not be identified. Empty your bladder when you get the urge, avoid constipation, keep the area clen and you will be OK