If you are worried, go to the doctor. Usually if there's no bleeding, there isn't much of a chance of miscarriage, but if it eases your mind, you can always go get checked. I had a missed miscarriage last year. lost the baby at 8 weeks, but didn't know until my 12 week ultrasound... Never bled. No cramps. I even maintained all pregnancy symptoms, so I've requested more ultrasounds throughout my pregnancy to be cautious.