at 7 weeks i went for a ultrasound. the baby measured up to 6 weeks & had a low heart beat, the doctor said it was early & the heartbeat will go up. i went 3 weeks later [3/18/2010] for a ultrasound & there was no heartbeat. my fiance & i have been having unprotected sex up to that day [3/18/2010]. my d&c is scheduled for tomorrow [3/23/2010]. is there a chance that i can be pregnant even though i havent had a d&c yet? im very concerned. thanks in advance.