We had an ultrasound today, i had my last period around the 24th Oct, which means about 4 week pregnant, but didnt see anything, the person who did the ultrasound also did say my bladder wasn't full, can that make a difference? Will our baby be ok??? We have 2 other children and i've always been able to see something around 6 weeks, could i just have ovulated later? and only be a couple of weeks?