Fertility Drugs & Breastfeeding

Quick backstory:

I had surgery for stage 3 or 4 endometriosis (I can't remember. It was 1 level below the worst stage) 3 years ago, finally got pregnant 2 years ago (after 7 years of trying) and now have a 15 months old that I'm still breastfeeding. I'm 32. They said the endometriosis wasn't the reason for my infertility and I also have PCOS "morphology" but not actual PCOS.

We really want to have one more, but fertility treatments while breastfeeding seems like a bad idea. Last time I gave myself shots in the butt along with an <a href="https://glowing.com/glow-fertility-program">IUI</a> and progesterone suppositories, and it worked the first time around.

We bed share, and I breastfeed him now ONLY to get/keep him to sleep. So 8pm, 12am, 6am, 10am, 1pm. I work full time, so he gets cow's milk about 40/60 mix, but I'm increasing the cow's milk every week. When he is sleepy is the only time he actually really cares about nursing. Otherwise he's to busy enjoying life.

My concerns are:

1) breastfeeding while taking hormones could hurt him

2) Breastfeeding while trying to get pregnant on very expensive drugs might make the drugs not work (it's $1,200 per try)

3) I'm not getting any younger

4) he's really not done breastfeeding and I don't want to force him because it still has benefits

5) slight increase in chance of twins FML I mean I'd still be happy but also FML... With a mama's boy toddler?

6) I really only have the money saved up for one try/cycle... So we'll have to wait probably another year and get some things paid off (my hubby's identity was stolen so we're dealing with a lot there)

Feeling guilty for wanting a second but it only gets harder to actually get pregnant the longer I wait. I'm basically told "there is no good time so if you want to do it you just need to do it"

Anyway. Anyone been through this before?