way too small. There's nothing anybody is gonna be able to tell you that will be anywhere near accurate. feed often and ask again in a few months. I had a pair of gt at 3 inches, I couldn't tell them apart til they hit 3.5 inches. then it was obvious.
a females dorsal fin stops well short of the tail, while a males dorsal will trail all the way to and sometimes past the tail. But that's something that won't help you right now regardless of what your fishes dorsal fin looks like. If he's a male his dorsal will get a trail, if it's a female it wont. males have more coloration of the body as well, while females have more bearding, but that is something that definitely has some grey area especially at a small size. If your males not dominant he'll have a more female color pattern. it's not cut and dry. feed him well and you'll know before you know it.
But for right now a coinflip would be just as accurate as anything else.