Multiple Sonogram

John • Happy Wife = Happy Life
Hi Guys,
I'm posting this in behalf of my wife.
Since we've got a BFP on the 1st week of may, our doctor ordered to run a blood test and have my wife undergo transvaginal ultrasound. She was 4 weeks that time, so all we saw was a Thickend Endometrium. Not even a gestational sac
Then our OB advice us to come back the other week to have another one. Then we saw a GS and a YS, but still no embryo. Then we were advice to go back in another 2 weeks.
We find an embryo and a good heart beat at 7 weeks.
Now we have another appointment tomorrow, for our monthly checkup, and we have been informed to have another ultrasound, this time, it's going to be just abdominal since we are on our 12 weeks.
My question is, is it normal to have an OB let us on an ultrasound in so many occasions? Or is it because we're going to pur 2nd tri, and this would be the 2nd tri exams? We don't have any idea. Our friends only had a couple (average of 3) of ultrasounds from day 1 to labor. We just find it weird that our OB treats my wife as if she is high risk. (She's only 24, with normal bloodtest and passed all prenatal screening)