Help! Plants look different?! (Pics attached)

Hi guys, first every grow - 2 plants (one seed Kush seed (feminised), the other White Widow (regular)).

They are on a 12/12 grow from seed, and 1 week in. They look a little different atm and I'm a tad worried - for example, the plant on the right has only 3 'leaves', the other has 4 fully formed ones. Thoughts guys? Attached are pics:

The plant on the right just lost a cotyledon. You will be fine.

They look normal to me. Don't worry about the cotyledon leaves (the first to appear before opening). Just get the light (if cfl) an inch from their tops to slow their stretch down.