Hey Sloane, you were right!
I just got back from the obst... and the 1:1,055 was my number... 1:161 is the average (or something) for a 37-year-old. Not for me.
Thanks for your messages... I kept telling myself if there was a problem the obst would have called himself. I just kept thinking about it on Sunday while I was waiting for the local equivalent of a tradie to arrive... then finish up.
I was so relieved when the obst explained it, even though I was reassured so much by Emmy83's comment.