Alright pink egg in starter town it is!
Pink eggs in general give a list of transformations you can see
here, so some may or may not be what you want. If you don't want your character's cock and balls to shrink, and you don't want them to grow a pussy, then you should us alchemy first. Assuming your goals are 1: Femininity, and 2: Boobs, you should use "Wild Melons" on Pink Eggs through alchemy to make it specifically grow breasts, and then you should visit the Stylists at the top left of Hawkethorne (starter town), and buy "Get Good Facial Scrub." It raises the femininity score by 10 when you use it, which is the same increase as Pink Eggs, but without needing you to do alchemy to make it
only raise femininity.
Also if you want your character's chest to get bigger than what the Pink Eggs can offer, a lot of race-specific transformatives can give bigger ones. For one you can buy, there's Bovum Sherry, which you can get from a guard at the bottom right of the map to the right of Hawkethorne (though if you go immediately, you'll probably be underlevelled).
Also also, in the forest to the top left of Hawkethorne, you can find a Witch's Outfit, which gives you tits and a feminine face (and a bigger ass) the first time you wear it. It can fast track things a bit without needing you to spend Electrum to buy transformatives, though finding it is a random event.