Pharmacy doesn't succeed all the time, but you can raise the chance of a success by putting more points into DEX and LUK, and putting on equipment with boni to these stats. A Priest's blessing and gloria is very useful as well. The skill Learning Potion further increases your chances as well by a big amount.
Or maybe you just forgot to buy Medicine Bowls (obtainable at the Alchemist NPC in Prontera and Alberta). You need 1 for every Pharmacy skill use.
For an embryo, you just need a potion creation guide, I believe. It may be cheaper, though, just to buy an embryo off another player, since the incredients are quite expensive, and if Pharmacy fails too often, you'll lose too much money.
