One of our speckled sussex approx 13 months old has a slightly pale vent and when we checked her vent we noticed a slightly swollen under her butt (maybe abdomen area). We have 4 other hens (3 roosters and one pullet) and are getting 2-4 eggs a day so I am unsure if she is or isn't laying. How can we tell if she is egg bound or if something else is going on? She eats fine, no pasty poop, no mites, and also sticks with the rest of the flock. Please let me know. THANKS!