They don't look pregnant. A pregnant female will have a rounded stomach. The female in the second photo could possibly be pregnant. How long have they been with males?
They only square off a few hours before birth. If it has only been a week chances are they aren't pregnant or are barely pregnant. It will be another week or so before any of them show any signs of pregnancy.
Post some photos in a few week and I can try and tell you how far along they are. They might not get pregnant right off the bat either, it took my females 2-3 months when re-introduced to a male to get pregnant.
The yellow one looks to have gained some weight. She could be pregnant, post some more photos in four or five days again and see if the other female has gained weight. Also get pictures in two weeks then we should definitely be able to tell.