My girl friend and I went to first u/s today thinking she was 8 weeks pregnant my girl friend and I went to first u/s today thinking she was 8 weeks pregnant they had to do a vaginal u/s and said they saw the embrio and emniotic sac and all that but they

If . If your girlfriend is only 6 weeks pregnant, then it may be too early to detect a heartbeat - even with a transvaginal ultrasound. A fetal heartbeat can be found more reliably closer to 7 weeks. Even though dating a pregnancy from the last menstrual period is one of the most accurate ways we have, it can still be off by a week or two. If you have concerns about her pregnancy, you should discuss them with her and her doctor. I've attached a page below that discusses early fetal development and what to expect. Good luck!
It . It can be very hard to predict the exact age of a pregnancy by the date of the last menstrual period, because it is hard to know exactly when fertilization occurred. The ultrasound is usually more accurate on dates. At 6 weeks 1 day it is not unusual to not yet see a heart beat. In the next week to two weeks they will most likely see a heart beat. Obviously if she has any concerns such as cramping or bleeding she should be reevaluated, but it is not abnormal to not yet see a heart beat.