your 4-5 days late, you can test any time now and will get either a positive or negative. I tested to find out if i was pregnant when i was 5 days late and got a positive reading. If you get a negative go to your doctors to find out what could be wrong, and if its positive go to the doctors as well and they will run a blood and urine test. But anytime is going to be just fine for you to test.
Other reasons, you may be stressed out about being pregnant, thinking of when you should test if you did it too early, and causing a late period due to stressing yourself out.
But test!
a blood test is more accyrate than a urine test from the doctors or a HPT aswell.
you can get one on the same day as you test to see if you are pregnant.
When i had mine, i tested a home pregnancy test the day before, and then went to the doctors for a blood and urine test.