Also keep in mind that tickets for a particular month go on sale at 10 AM on the 10th of the month prior. So for example, tickets for April will go on sale on March 10. And they will run out fast.
I went at 9.50 am on the 10th to buy 2 tickets for the following month, and there were already 2 people ahead of me in line for the Loppi machine. One lady must've bought at least 10 tickets.
In my experience it is next to impossible to find any tickets for the month you are in. I bet March is all sold out already.