mold or minerals on my pot?

So my beautiful large monstera is growing in a terracotta(?) pot and i had hoped to postpone repotting till spring. Today i noticed large amount of what i assume is mold growing on the pot. I searched this sub already and a lot of similar images say its just minerals, but mine have a little bit of black undertones so i am very nervous that its actually real mold. Could anyone help me to understand what it is exactly? I water it every 1.5 weeks and it receives sunlight in the mornings Thank you in advance