because mt bmi is high mw has said at 28 weeks i have to have a gtt if i want a home birth..ive never had any sugar in my urine.. so y do i have to have this test? if theres no sugar ever in my urine.. and at 28 weeks i go for normal bloods.. can i ask for a urine test, to see if i have any sugar in my urine? if i dont why should i have to have a gtt?