When will i ovulate if my cycle is every 34 days & my period last 4 days?i take lh test but they always come out negative.i never miss a period.

About day 20: With a 34 day cycle you should expect to ovulate around day 20, give or take a few days.

Around day 20: Take the average length of your cycle and subtract 14 days (34-14=20) to figure out your approx day of ovulation--i bet you are testing for ovulation to early that is why you are not picking it up--do not start testing until day 17 and test for 1 week. Make sure you test with concentrated first morning urine., if your having trouble finding the surge.