help!

Ask ko lang, 37weeks and 4days naku, all my previous results for urine are okey, andalakas naman ako uminom ng tubig every day even diring night , actually last night until this morning naka 2.5liters naku ng water. Pero kanina madaling araw until now ang sakit ng huling patak pag umiihi.. anu po ba ibig sabihin nun???