I wouldn't worry about having tapped too early, esp for this area. You've only tapped for one year so far, that's not enough time to get to really know your trees. Each time I collect I keep track of how much I get from each tree, each day...so now I can look back over 10 yrs worth of records and see what the historic record says for each tree. Mind, my bush is only 8 trees! :-)

I've only got just over a gallon of sap so far but my big trees haven't even started yet, and generally don't really get going til a good 2 weeks in. My little bush maples are the ones producing the most so far, and stayed pretty consistent from start of the season to finish. Just be patient, this warm weather should help.

If you like I can visit and take a tour of your sugarbush and give you the benefit of my experience.