Sequential screening results

Hey ladies- just want to share to see if anyone else has been through this. All measurements were great on ultrasound, first blood work was great but second blood work results came today. I got a call from my doctor and she said normally at age 28, the chance for Down syndrome is 1 in 270. Something was off with my test and mine is 1 in 150 now. Still really low and doesn’t change anything at all for us (we are beyond excited for this little babe and know God has knit him together perfectly) so I’m relaxed but it did catch me off guard a little. They want to send me for more testing at the maternal fetal medicine doctor. Has anybody else gone through this? I’m 18 weeks on Friday