How late do you have to be till you know you're pregnant?

I would say about 7 days after you period is due you should be able to take a pregnancy test and it show + or - sometime a urine test might still come of neg and even sometimes blood says a non pregnancy if you hormone level is low and the urine test will come of neg. if you HGC levels are low. So the best time to take a urine test is the first pee in the morning because it is the strongest urine sample that you would have for the day