Am too lazy to find the post, but am pretty sure I saw NWS say it has only happened in 4 previous years.
EDIT: Haha...not like I got sudden ambition - just happened to come across this after having made my post:
"In the Atlantic record of tropical cyclones going back to 1851, only five other years have had two systems recorded to have reached named-storm strength (sustained winds of 39 mph) prior to the June 1 start date of hurricane season. It’s a good bet that at least a few pre-season storms were missed in the pre-satellite era. Here are the known years with two pre-season storms, as compiled by James Kossin (University of Wisconsin–Madison):
1887: Two tropical storms (May)
1908: Hurricane One (March), Hurricane Two (May)
1951: Tropical Storm One (January), Hurricane Able (May)
2012: Tropical Storm Alberto and Tropical Storm Beryl (May)
2016: Hurricane Alex (January), Tropical Storm Bonnie (May) (note that Alex is arguably a late storm from the 2015 season rather than a super-early 2016 storm)"
Full article here: https://www.wunderground.com/cat6/that-was-fast-tropical-storm-bertha-develops-and-makes-landfall-over-south-carolina