happyharry,
Great gains. Don’t be too surprised if your gains don’t continue at the same rate, if you make 1/4” next month be grateful. A fair number of starting PE’ers gains around 1/2” in the first month, much to the annoyance of those who don’t.
One thing that is worth mentioning is measuring. If you measure within 2 days of your last PE session you are likely to be measuring the temporary pump from your sessions. Make sure you press hard into the bone and take two days out when you measure (the end of a second rest day). There’s nothing worse than over measuring, it means you suddenly stop growing or go backwards.