Are the dog's nipples a bit large and not very dark in color a sign of pregnancy?

Hello. Just from this description, it's impossible to confirm whether it's pregnant or not. The behavior of the female dog hugging your leg can also mean claiming sovereignty, and it's not necessarily a sign of estrus or nymphomania. The gold standard to confirm pregnancy is to take it to the hospital for an abdominal ultrasound at least three weeks after mating to determine.