a couple of things...

do you have 2 plants growing there in the same pot? thats not a good idea as the roots from both plants will get tangled together and they will compete with one another causing one to have stunted growth... also if you discover one is a male down the road it will be impossible to pull out its roots without killing the other one... and if you just cut it down and leave the roots, the roots will rot and possibly kill the other one.

other thing is that you have your seedlings in a rather large pot for the size of them, if you put them in really large pots off the bat the roots will stretch out early on and not fill the pot properly which will make them much less effecient... theres a threard in one of the forums thats a really good overview about transplanting and why its important, but i can;t find it at the moment