首先是受孕时间和检查时间：
Because mice usually mate 4-6 hours into the dark cycle, look for a plug as early into the light cycle as possible.
Otherwise, the plug may be dislodged or dissolved.
然后是为什么又阴栓也没有怀孕：
The presence of a plug indicates only that the female has mated, not that she has
conceived. Pregnancy may be verified by palpation on the eleventh day of gestation (day zero is the day a plug is found).
所以看起来似乎最早的判断是否怀孕的时间要等到11天以后了。
引用来自Jackson Lab 的"Breeding Strategies for Maintaining Colonies of Laboratory Mice"
