Do pregnant rats gape before birth?

[bentleek13]

So I have a rat that I suspect is pregnant. I just checked on her and it seems that her vagina is a bit wider than before. I’m not sure if rats get wider down there before birth, or if this is a sign that she’s in heat and therefore I can rule out pregnancy?

 

[mvZD]

The vagina will be open when they are in heat. If she is pregnant she won’t really start showing until the last week or even last couple of days and then it will be incredibly obvious that she’s preggo.