Indeed I made a mistake to introduce them and now separating them perm is not an option since they are so well bonded.
Actually it is an option; there are no cases of chins dying from depression because they were separated. They are not bonded; they do not love each other; they want to do one thing and one thing only and that's mate. You are projecting human emotions to them. It is an animal's instinct to mate and reproduce...there is no love involved.
Please do what's right for your females and separate them from the males until they get neutered. Of course they may be pregnant already, but at least they won't have a male chasing them around constantly because he wants to mate. I hope you don't have more than one male in with the females....they can and do fight to the death over females. Or, an annoyed female can attack a male. Chin fights are NOT pretty, they are brutal and certainly can kill each other.
Pregnancy can be very taxing on the female. If they are not large enough, they may not have a large enough pelvis to pass kits. If that's the case, the female AND kits could die without an emergency c-section which costs a lot of money. Not to mention all the other things that could go wrong- take a look through our breeding and babies horror story section.....
Since they are from unknown backgrounds came out of bad situation, don't you think they deserve to live out a worry free life without having to be chases around by males that want to mate them? And they definitely do not need the stress of raising babies. There are tons of chins that are in the same situation those females were in and sitting in rescues that all need homes- just like dogs in shelters- you shouldn't contribute to the population without the right intentions.
You'll need to get a baby safe cage and start counting 111 days. If they are pregnant they will need to be placed in this baby safe cage and you will need to start taking all the precautions and readying yourself by reading through the breeding and babies section.
Please don't take any offense. I am just saying what needs to be done for the best interest of these poor girls.