Why am uncomfertable before i urinate.?

hello ladies, i would just like a bit of help, am 17 weeks pregnant, and from about 12 weeks i have been really uncomfertable when i have needed a wee, not painful but were baby is it goes hard and i cannot lean over, move around until i have emptied my bladder and it makes it awkward to walk, i have just been diagnosed with SPD (symphysis pubis dysfunction), does this have any relation to it? it is worse if have been sat down with a ful bladder, thankyou x