Are you asking this to check the DNA test you had that told you Guy B is the father? Or, did the test merely rule out Guy A and now you are second-guessing the test results? (Sometimes women only test with one guy, especially if they are keeping the sex with him a secret from the other guy, and then they get nervous and in their nervousness, decide the test might be wrong. Is that what's going on here?)
Since you said in a different post that your period arrived on the 5th, the "fertile period" of June 12 to 18th that you name here isn't going to be quite right even on its face. It would be more like June 14 through 20th, if you take into account the average lifespan of sperm, an average woman's 2 weeks from day 1 of last period to ovulation, and the average viability length of an egg, and a target date for ovulation based on average cycles would be more like the 19th.
But unless you were using an ovulation predictor kit, you can't even be certain of any specific date for ovulation no matter how you count out the "fertile period." (And even if you were using an ovulation predictor kit, it could only tell you when you have a hormone surge that should lead to ovulation within a day.) The problem with assuming an ovulation day based on averages is that you don't know that this average applies to you.
Anyway, you tested with the DDC. They are a reliable lab and have ruled out the first guy. Unless you want to do a "discreet" test with Ravgen (you send in the second guy's toothbrush or a swab from the edge of a drinking glass) for further big expense, take DDC's answer as correct. Saying "what if? what if? what if?"when you have an answer from a reputable lab will only drive you nuts.
I’m confused. I thought you had your answer.