100% here. There are a couple of different ones around and they also say to use your lunar age which is different to our actual age when using the chart ones. The one I used was the one where you use the drop down of your date of birth, time zone and then next line put in the conception details. It was right every time.
I also had confirmation from the ultra sound (just me not DH), although I was a little sceptical of both with my Third .