Help!

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 eve 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