Mama, please go to your doctor or clinic right away, UTI during pregnancy needs proper checking para sure ang baby is okay. Hindi ito something to worry about alone, alam mo yan ng doctors na! About the uterine tightening (Braxton Hicks), normal yan during pregnancy, pero the dark yellow urine + holding your pee, those things together kailangan talaga ng professional check. One of my mum friends had similar concerns and relief lang ang naramdaman niya after her OB checked her. Don't hold your pee ha, that can make things worse! Go to your doctor or midwife para ma-ease ang mind mo, they'll make sure everything's fine with baby.