My wife went to bathroom in middle of the night she says she noticed a tiny drop of blood on tissue thah she wiped with, she’s pregnant (7th month) and she also has a rash in the area due to razor shaving before she went to sleep. thank you so much for this sevice

Shalom, In this case it would appear that she is not niddah since there is a probability that the blood came from the rash. Kol Tuv