I have muti plant in one pot.

I have 3 plants in about 5gal pot. I'm really just wondering if I will be having any problems maybe. They really haven't be showing no big problem. The only thing I'm worrying about is one plant is going to be later then the others to harvest. Also it's a clear pot too. I see a a dozen roots is that good?

U never want roots to see light and u don’t want to put more than one plant per pot you’ll learn why

As said above you dont want your roots turning green due to light contact and those plants gonna have to kinda fight it out if they potted together your yields will suffer big time

I've used clear pots without problems. If the roots aren't turning green there's no reason to worry about them. The more room your roots have to spread out the better your yields will be, so separating the plants, if they're young enough to do so without much damage would be a good idea.
Unless you're planning to switch to flower in the next week or two, they're going to need some time to recover from the transplant stress.

Just rap the pot to be sure, not much point taking any extra risk for the sake of 5 min work.

The 3 plants will be fine depending. If you are not veging very long they will fill the pot and then act like a single plant that has been topped 'ish. You'd need to do a little trimming of lower leaves in the middle but essentially you are starting with 3 medium size colas instead of one big one. With a little separation you could do good from there. But then you'd have to selectively top if one is bigger than the others (if indoor). If the later runner is more than two weeks I wouldn't do it personally. Thing is, if you harvest the others, their roots will begin to decay. I can't see this being good for the remaining plant, 2 weeks is just a guess though.

Multiple plants per pot is something I am considering doing for faster veg times. If done right it's not much differant to a high count sog type of deal. But much easier to manually feed, due to less/bigger pots. Great way to easily fill in the canopy with only some selective topping too.