Tilt uterus

So we went for our first scan which according to my lmp im 7.5 weeks. Doc measured baby at 8 weeks so im ahead. Freeky part was when he did the ultrasound we couldnt see anything at all that how far back/tilt my uterus us. We did a vaginal scan could only then see our little peanut. Anyone else experience this before. Doc said nothing to worry about and should be back to normal at 12 weeks.