congrats - princesspreg! (I remember you from when I posted about my LO's arrival!)
My statistics for this aren't encouraging perhaps, but mc in August 2009 and two possible chemicals over the subsequent year, but found out I had an underactive thyroid in Jan 2011, medication adjusted in May 2011 -- positive test the following month (!) - the month we were going to start IVF and, LO born in early February, so either two (2) years or from January 2011 (as thyroid condition appears to have meant limited ovulation (tests done over 2010....sigh), so about six (6) months from that point. Oh, and I was 43 when conceived!
best wishes