Has anybody done a home DNA test kit on their alleged childern/child before?

My boyfriend and I have been together for 5 years. He has had health problems the last two years and since has been back at work and doing better. His EX is trying to get him for back pay the two years he was sick and didn't work. She has treated these 2 girls like her property and gives and takes his visits as she sees fit. Things are finally going through the court system now so we can have a payment plan and visitation plan so she can't do this crap anymore. The last 6 years he questioned the paternity of his 6 year old considering she was seeing another guy off and on the whole 6 years they were together and the child is just completely different in every aspect. We suspect the father may be her fling she is now with and has been with since they separated. She denies cheating when he had very clear evidence for example a hickey on her neck, several people telling him, actual semen inside her pants....ETC. I don't mean to be graphic but that is the truth. So we recently swabbed the youngest to finally put this all to rest. We will have the results within the next 5 days. I'm wondering if anybody has been through a similar situation and how did it turn out for you? Where your suspicions right or did your gut get proven right/wrong? Note* that he always paid child support until he took sick and is going to begin once he has a month in so he can see what his income is going to be* He is the furthest from a dead bead Dad and has always been very involved when he was allowed!