Either way you have to go and see the doctor/midwife anyway, and i dont think its a ridiculous ask for your parents to ask for you to go and get it confirmed, it probably wont sink in for them until the doctor confirms it. However, if you are from the UK? They dont usually confirm pregnancy at the Drs they take 2 positive preg tests as a POSITIVE, as they use the same../ They just book you into a midwife appointment.
If your boyfriend isnt being supportive now, who says he will be in a few months time? However it probably jsut hasnt sunk in for him yet.
Many people say that women become mums when they become pregnant and men become fathers when they see their child, hopefully that wont be the case!
I say just get through the first Dr appointment and then go from there with your plans
its good that your parents are supportive and i dont see why your boyfriend seems unhappy about that, unless he's a bit jealous that they are involved and he wants the whole experience to be about you and him?
OR maybe its the fact if its confirmed, it will all become real to him and he doesnt want to admit that to himself yet?
Anyway good luck and congrats