Looks like the blue/purple one in the top left corner of the pictures is going to drop soon. That black spot you can see is the gravid spot. It is at the bottom of where the body meets the tail of the fish.
The one to the right of the male in the picture is hard to tell. If she is pregnant it will be a while yet.
I would let nature take its course here. I had 4 guppies, 2 males and 2 females which exploded into about 30+ fish. I gave away 12 (6m6f) and fed the fry of the others to my Angelfish. The parents seem to eat the fry for the first few batches of fry, then they grow tired of chasing them it seems.
Is this a guppy only tank? If there are other fish in there they might eat the fry also. Hope it helps and good luck!
