Aloha Mona,
I don't want to alarm you unneccesarily as I'm just a random person from the internet... but you might want to talk to the doctor on the phone prior to your appointment and see if he wants to see you sooner or have you stop dilating until he can see you. It could just be from the constipation, but you could be injuring the wall between your vagina and your rectum. If this is the case, it could develop into a rectovaginal fistula.
Again, don't panic. That is probably a worse case scenario. But do talk to your doctor immediately. It may all clear up after you get the constipation dealt with, but better safe than sorry.