Potty training and going to nursery.

I have just started to potty train my 2 year old boy and he is doing quite well. Day 1 got off to a shaky start with 6 accidents in the space of 2 hours, but once he had done a poo (sorry if TMI!) he was dry for the rest of the day. Day 2 he completely refused his big boy pants and although I did get a couple of wee's in the potty he really wasn't too keen. Day 3 he was dry all day. Now on day 4 and he has been dry so far. He is just wearing proper big boy pants, then I put pull ups on for day time sleep, which have so far stayed dry. Obv, still wearing nappy at night.
Our only real problem is poo's, he's not yet done one on the potty. He's not used to sitting down to do a poo, he always goes and stands in the corner, and is still doing this with his pants on. So far i've not been quick enough to spot it in time!
Tomorrow he goes to nursery and I really don't know what I should do. Should I put him in pull ups all day and ask them to take him to try for a wee regularly? Or should I just ask them to carry on doing what I have been doing and put up with the consequences? I don't want to confuse Ollie by changing things, but at the same time I don't want him having accidents with other people.
Also, anyone got any ideas on how to get him to sit down for poo's? Are poo's harder for them to control? He stands up to do a wee - he likes to be a big boy like Daddy!!!

Any suggestions would be very welcome. Nicola. xx