Just a few questions to help get a better picture to give you the best answer possible, please.
Have you taken a gravity reading to verify whether it is done?
What yeast did you use?
Did you rehydrate with GoFerm?
A hydrometer is a vital piece of equipment that can tell you a lot about where your must is at in the ferment. End of May-end of June, it COULD be done, but, only way to truly tell is with a reading.
Depending on the yeast you used, it could've eaten through all the available sugars already, but again, a reading would tell you a lot.
If you didn't/ don't regularly rehydrate with GoFerm, I highly recommend you get some & use it every time you make a new mead. GoFerm has vital nutrients to give the yeast a head start in maximizing the colony, therefore producing a healthier ferment. If the yeast are happy, not always, but, generally, it is done a little faster & consumable a little sooner.
I hope this helps you.
Happy meading