I haven't quite been in this situation, but something similar. I concieved our DS with IVF and wanted to do a unmedicated Frozen Embryo Transfer with our remaining embryo when our DS was 12 months old. I spoke to my FS about not wanting to give up BFing and so we did blood tracking for a month after I got AF to see if I was O'ing, and I wasn't. In fact my levels remained baseline. I had had 2 AFs before we started tracking, and my Dr basically told me that if I wanted to try again, I'd have to stop BFIng. The fact is, atm the most likely reason that you are not conceiving is because you're BFing.

In the case of Clomid, I suspect that BFing would be an issue because of the possibility of crossing into breast milk. I don't think there is any evidence that it does or doesn't and you'd have to weigh up the risks of it. I have also read that clomid can inhibit your supply of BM.