We have had experiences with both centrals and colombians and there is a huge difference in breeding.
Colombians, we put our males in on halloween every year by habit. We leave them in there till there is absolutely no interest. If there was no interest to begin with, we take him out and use on another female till we find one that he starts courting. If you cna read your animals well, then you do not need an ultrasound, but an ultrasound removes all doubt
Once the male SHEDS, we always know he is done or she is.
We have put males in with females and missed, either ova were starting to shrink again, or already gone. If she is developing, and undeveloping, a male will not stop trying to breed. Those same females years ago , we thought were "bred" and would have no litters. this year was weird for us cause we started putting some males in, then had a change of plans in what we wanted to breed so we took them and switvched them out or completely. Some of those females didnt see a male again this year. Some of those females(colombians) had super low fertility counts, which is a first here for us. Our fault for taking males out and using them elsewhere. The elsewhere we used them , we had great breedings and babies. Now for the centrals, I have no idea
but we had certain males in with certain females for only a 2 week period, if that, and had two perfect litters, not a slug?!
second time that happens here. They breed almost immediately, and not too much courting on pure centrals. Our experience anyways.
I have also noticed females with less food, have had better litters for us this year then the females we thought needed to be fatter.
Aslo if your sabogae is losing weight, getting real distended, money says it will be a good litter. If she is fat, and sometimes when you look, she looks gravid, other times no, then you might get a so-so or slug litter