Is it safe for dogs to get stuck together repeatedly?

Ok first of all, I am aware of the overpopulation of dogs so please do not respond to me telling me all about that. I have saved SEVERAL animal lives from pounds and given them life-long loving homes. I now have a 1 year old male Chihuahua who I have an appointment to get neutered and a female that I just rescued from someone who was going to send her to the pound. She is also a Chi. When I took her in I didn’t ask any questions including “is she spayed” because I knew that my male was already scheduled to be neutered. Well what I didn’t know was that she would actually make herself come into heat because of my males presence. I really thought I would have at least a month before she would come into heat. Well… It didn’t turn out that way. She came into heat without me knowing and the way that I found out is that they got stuck together. I tried to keep them seperate but apparently where there’s a will there’s a way and I have now walked in on them several times stuck together. Last night I caught them again and my female was attempting to chew my male’s private part off of her. I am worried because I don’t want her to hurt my male or vise versa. Is it safe for them to continue breeding at this point? I’m sure she is probably pregnant unless one of them is somehow infertile. I have tried keeping each of them in a cage but the female can climb over anything and she gets out/in whatever cage she wants. I guess I should have bought them each a kennel but it’s a little late for that now. I have every intention of getting all of the dogs and puppies proper vet care and shots and dewormed and all of that good stuff as well as doing a very thorough screen on anyone who is interested in adding one of the puppies to their family. Now I just need to know, what if she is pregnant and they keep breeding? Also, it’s been a couple weeks now that this has been going on and she still appears to be in heat. Is this normal? My male is scheduled for his surgery in 5 days. Will they be safe together until then? Also, will he be able to “get stuck” after he is neutered or does that function go away?