My DD has had a really tough run at her daycare. As wonderful as it is, her group has lost *5* educators in the last year. I don't know why but her group is just unlucky in this respect. It has resulted in a lot of delays in behaviour in many of the children in the group. DD is 3 and not even close to being potty trained for no.2, and she has regular pee accidents. The new educator who's taken them on is very skilled with 3-4 year olds, and she tells me that it's very common for toddlers to cling to babyish habits whenever they feel insecure. Seeing as I'm a big believer in attachment parenting, I've tried to compensate by giving DD a lot of physical closeness/hugs (she also sleeps in my bed and has since birth), and one on one attention.
I find the regressions come and go depending on how she feels day to day. When I initially separated from XAH and there were visitations, she was 15-22 months old, and her behaviour was ERRATIC after ever visit. I think that's partially why I nursed her for so long...I wanted her to have that sense of closeness with me. With respect to potty training, I've also resolved not to force her because she's obviously holding onto that form of control at the moment. I just keep telling her "when you're ready, you'll know".
*hugs* to you mama. I know how you feel.