I'm pregnant with my third (Juuust pregnant, I'm guessing about 5-6 weeks, but could be as far along as 8 weeks). My dates are not at all for sure, since I was on hormonal birth control (it's a really long story as to why).
Anyhow, my daughter is 2.5 and still nurses once per day, before bed. I'm having some fairly significant spotting (I did with her too, and went through HELL for 6 weeks before finding out all was well) and I definitely notice some tightening in my uterus when she nurses.
Do I need to stop nursing her? She would be devastated, she loves her milkies.