Are Home DNA Tests Reliable?

My daughter and her father took a home dna test i did not take the test with them i breastfed my daughter mins before she took the test and I'm quite sure my boyfriend brushed his teeth as well before taking the test the test came back my daughter wasn't his it came up 0% but how is that so if the matched 10 marking out of 15 would if have made a difference if i have taking the test