I breed rodents at home and work in a research laboratory. At work, the lab has their own breeding colonies. So it's pretty much scientifically known.
Are you sure its a single female giving birth over a span of 2-8 days?
There is no "next ovulation" once the mom is nursing the pups and the heat after birth passes. The next one should take place once the pups are weaning or weaned.
To the OP: for 3 mice a week, you probably just want one litter a month give or take.
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