Help me am i going crazy?

ok im due aug 15 i think well my last period was on nov but it was only 3 days long i go about 5 days.my due date is going by nov but, my family all say that i was glowing around aug and i started showing around oct. i get really bad cramps at night and i cant walk from one side of the store to the other with out cramping really badly my doc said that its just my mussels getting big and that's it, i don't really believe her but i go with it. im just asking what everyone thinks, oh and this is not my first child its my 2nd my first i went 3 weeks past due date and im felling what i felt then so that's why im asking. Thank u for reading