I recently adopted two ball pythons from a person locally. Well needless to say they were not to familiar with snake husbandry and kept them both in a 55 gallon aquarium. Well I fed them both and they both ate fine and I sexed them turned out they were male and female. The male even had a sperm plug. Anyways, they havn't shown any sign of aggression and both have shed since I got them about two weeks ago. I've held the female many times and it never hissed or struck. Well today I reached in and the female acted a bit skiddish, and kept hissing at me? Could she be gravid? How method could I use to check. She doesn't seem much bigger from the time that I got her. Thanks for your time.