Help!

Throughout this month me and my boyfriend have had unprotected sex around 15 times maybe on top of the protected.
My app which tells the due date of my next period is saying that I am six days late, my other app is saying 3 and <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> is saying today is my due date. I know there is a high possibility that I am pregnant but I am worried because my boyfriend isn't taking it seriously , he is 17 and I am 15 we have been together just over a year and I don't really know how to get him to talk about the subject as everytime I bring it up he says don't worry you'll be fine and he'll be here for me 100%?? Any ideas on how I can get him to talk more about it and take it seriously