Won't go potty at home

We have been trying to train our 2 1/2 yo daughter for almost a
month. It started out kind of rough and we switched from panties to
pullups (at daycare's request). After that, things were good. She
would sit on the potty a couple of times at daycare, sometime
succeeding and sometimes not. On friday, she was dry ALL DAY at
daycare. Yeah. I thought the end was near. She didn't use the potty
at home all night. she went off with my dad saturday night and stayed
dry all night (except for poop, still working on that), and was dry in
the morning. When she came home, failure again. She used to go
really good for me at home, but recently, she had stopped. Whenever I
ask her, she says she doesn't have to go. When she has an accident, I
try not to get mad, but it is getting hard. I know she knows better.
Any suggestions?

Also, on friday, my husband left on a business trip for two weeks,
could this cause her sudden regression at home?