4 year old regression

I have a 4yr old daughter that for a short time was 90% potty trained. we had the occasional accident but most of the time she went in the toilet. Since around December she has regressed worse and worse. She on occasion will say she needs to go potty but now most of the time she will poop or pee in her pants. She says she doesn't know when she needs to go but sometimes will say "I need to go pee or poop" so we know that she knows the feeling. Most of the time when these "accidents" happen she will crouch down in a corner and just do it or will be playing and I discover it a little later. The only thing that we can think of that might be a problem is I have started college recently but she is in preschool so I take her to school and pick her up from school. We can't figure out how that would affect her though because she has been going to school before I started and my hours are after she goes in and before she gets out so she shouldn't even notice me going to school. We have tried rewards of various kinds including star charts candy, and prizes. We have also tried punishments of various kinds, like taking things away withholding prizes and timeouts. nothing is working. we took her to the doctor and they tested for a urinary tract infection but it came back negative. What do I do I am at such a loss.

[margypops]

Many small children do not like asking to use the bathroom when they are at school, it could be she needs reminding, and has got into a habit of not going, it may be upsetting her, speak to the teacher and find out if they remind some children to use the bathroom. It could be having a knock on affect at home, I suggest more supervision at home so she isnt able to do it in corners in my opinion punishments do not work for this kind of thing it only creates an anxiety about going and feeds upon itself. Take a step back, lessen the emphasis about it ,be aware and around her .Good luck