HELP!! Pressure canner: need info NOW!

[I loveStitchnippyjon]

I am using my Presto pressure canner right now for the first time. I followed the directions exactly, but I put the weighted pressure regulator on at least 20 minutes ago, I can hear it boiling pretty hard, but the regulator is not "rocking" like it should!
Should it be taking this long?

 

[I loveStitchnippyjon]

OK, it eventually took 45 minutes of boiling before it started to rock. This is nerve-wracking! Maybe I should go back to my old water bath canner.....