I used up all my gold coins from quests on eggs and got 3 hatchlings, I’m trying to catch the last one in the spot every says you catch it and after about 7 hours of farming the same spot I’m getting pretty pissed off haha 
how longs it supposed to take to catch?
Forever and 3 days exactly. It’s al random I farmed for about 24 hrs non consecutively and got nothing. Farmed for 30 min while helping my other half study and I got 2 of them. That said the first battle is being in the right spot, then persistence, and a good luck charm don’t hurt.