Why do my 6 inch tall plants already have pistils and balls?

This is my first grow. I have learned a ton from other peoples' posts and other internet research. I've done the absolute best I could with limited funds as far as lighting and what-not. I even purchased seeds from over seas. I had 8 plants growing. They were all planted within the same week and range in heights from 5" to 18". The two taller ones don't really show any signs of sex. There is one about 6 or 8 inches tall that has OBVIOUS white V shaped pistils at the 5th and 6th nodes. One 5 inch one had OBVIOUS balls growing so I pulled it. I pulled 2 more 10 inch plants last night that were showing ball-like growths. Doesn't this seem a bit early for sexes to show? Or am I just not experienced enough. I've had them on 18/6 since showing through the soil. I never switched them in to early sexing, was just gonna wait it out. If they're already sexing, can I keep them waiting until the taller ones do too? I only have one room for veg AND flow so they need to be in sync.

Images: the first one is an overshot of "garden", the second is the little guy (5inches tall) that I pulled (in the first picture, he is in the small white container), and the third is one of the plants I had to pull last night.

Advice?

I'd switch to mylar instead of tinfoil, It'll burn your leaves. They have "emergency camping blankets" at walmart for 3 dollars a piece, they are thin and hard to work with but if you attach it to the wall well there shouldn't be any issues. I wouldn't just start pulling plants either, without being really sure, did you buy feminized seeds?

that is a set of balls, and what your thinkin is a pistil is actually a stipule. Present on both male and female plants

Looks like you may have a few autoflowers mixed in there possibly. They are short and usually start to show sex around 2 weeks, even with 24 hours light. It might of been a mix up in seeds.
here is an example pic.
View attachment 1475941What strains if known are they??

What strain ?
Somethings a bit mixed up.
Auto's there is does seem.

the strain I bought is master haze, but I threw a few bag seeds in as "practice" since it was my first time. I only germed 5 of the MH seeds, so maybe 3 or 4 of my plants are those, the others are bag seeds. I only pulled the ones with the obvious balls. I didnt have a good picture of the one with the pistils, but I will. I DO have a couple feminized seeds that I am saving for when I'm good at this LOL. (and about the emergency blankets, thanks, will do!)

tell me those aren't pistils. No balls on this one at all, but only about 8 inches tall.

a little early to show sex...no..ive had autos that sex at 12 days old and 3 inches tall....and reg strains under 12/12 that sex in 20 days...the odd part here is master haze is not an auto...and neither will be your bagseeds...so why are they sexing at all if your under a 18/6 cycle right now....something doesn't sparkle here....are they on a timer?..if they are your timer is off by about 6 hours....and as it comes to the tinfoil...long as your not using really high powered lights your fine...but next time to make it easier forget the foil..forget that thin mylar bullshit and just toss up some white poster board...or flat white...but thats the least of your worries....need to figure out whats going on with your lights to make them flower on a 18/6 cycle

They are on a solid 18/6 timer that I check on constantly to make sure it is working. It goes off at midnight and on at 6. I am just going to go get some HPS lights this weekend and see what happens when I start to flower them. Might as well. Two of the plants are like 2 feet tall with 8 or 9 nodes and 3 of them are about 8 inches with about 7 nodes. (one plant is still too tiny, he was a runt)