If you're worried about the April 1 changes but feel you need more time ... look for cancellations on the Pearson website.
I too was scheduled several weeks in advance but, at my testing site at least, there were always last minute cancellations the day before and, there were even more last minute cancellations if you were willing to drive further to other sites. You could probably do this all the way up to April 1 if you wanted to.
They'll let you take those cancelled slots at any time ... you just need to make sure you cancel or reschedule your own appointment 24 hours ahead of time.
When I was ready, I just looked for last minute cancellations ... and, sure enough, I was able to take the test the very next day.