Maybe you should get some lube first and try that before going to see the doctor? He may be exceptionally large, you exceptionally small, and that you need to stretch out a bit (vaginally as it were) before it will be "workable"
Every time I have slept with my wife for the first time in a while (IE: a month due to when we were dating long distance or whatever.) and lube wasn't specifically used I would cause her to bleed. When we are having sex regularly (usually) this doesn't happen quite as easily, but I still use lube religiously.
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."