First thing's first; Merry Christmas to Susans.org, it's staff and it's members, and I hope you all are having a wonderful holiday season.

Anyway, I'm wondering when I should probably ask my doctor at the Mazzoni Center to put me on oestrogen. I did some research about it

My doctor wants to change my regime anyway. During my last visit to that clinic she's been talking to me about me taking my estrogen in the form of an injection. After she and this other doctor showed me how to use it, she asked if I wanted to start on it in December or hold off until January. I decided to wait until January, only because I already spent nearly $60 on my estrodiol and spironolactone.

Because i have no intention on getting breast implants

Just to be clear, I'm not trying to rush anything. I just learned that oestrogen can really help with breast development and facial feminization. I'm really hoping to have d cup size breasts because i don't want implants. I just really want to give my body sufficient time to develop and feminize itself before i undergo any surgeries. Then that way I know what i do and/or don't need.

Hate to break it to you but the majority of transwomen won't end up with D-cups. A few do naturally if they have the family genetics to back them up but the rest of us a lucky if we get to B or C.

As for estrogen injections, if you are taking estrodil then you already are on estrogen. And yes, that is the usual way to grow breasts. Progesterone can be added to the mix (maybe as an injection, but I haven't heard of that) - but the jury is out on how it effects breast development (some say yes, others swear no). It doesn't sound like your doc is changing your medication, just the way it is delivered...??