I have been cubing since March, maybe like February, but March was when I got my first cube. I am about a 28 second average too. I dropped like 4-5 seconds in not even 2 weeks. I cube a good portion of the day, with a hundred or so solves. I would say you are doing good with your times so far, but it depends on how long you actually cube, not just when you started. I probably have more practice time than you, so you might be doing better than me. I averaged at like 32 when I switched to Fridrich from full beginners method.