it is possible that you could be pregnant the best thing that you could do though is just take a pregnancy test. if you dont have a friend that can drive and help you get one than talk to your school nurse, it might be a little embarresing to talk about but a lot of school nurses have home pregnancy tests that you can take. If you period is that late and you havent had one for May than either you are pregnant or something else is going on with your body that needs to be checked out. It souds like you might have some
pregnancy symptoms. so I would def. test with a home pregnancy test like EPT
As for not being ready to settle down and have kids, very rarely does a young person feel like they are but you have may have created a life and that means you are an adult now wether you like it or not and have some decisions to make. it is hard to be a young parent, i struggle at it but I love my son....if parenting isnt right for you quite yet there are many couples out there that are waiting for a child b/c they cant have their own.
Best of luck!