feeding over a year, now my are really sore. Am I still making enough milk?

I am nursing a 14 mo old. I have never nursed any of my children this long, but I am trying to let him wean on his own slowly, he's just taking his time. I was pregnant in Jan and Feb and my were very sore then. I miscarried and had a d&c 5 wks ago. They have been fine since. Now they are very sore again. I do not appear to have thrush and neither does the baby. I guess Icould possibly be pregnant but I didn't think so because it took up until last week for my hcg to finally go back to zero from the m/c. Could I be not making enough milk. I have poison ivy severly right now, could that affect them? I don't have it on my but it is on my a little. Thanks and God bless.